Thermally induced processes in mixtures of aluminum with organic acids after plastic deformations under high pressure

NASA Astrophysics Data System (ADS)

Zhorin, V. A.; Kiselev, M. R.; Roldugin, V. I.

2017-11-01

DSC is used to measure the thermal effects of processes in mixtures of solid organic dibasic acids with powdered aluminum, subjected to plastic deformation under pressures in the range of 0.5-4.0 GPa using an anvil-type high-pressure setup. Analysis of thermograms obtained for the samples after plastic deformation suggests a correlation between the exothermal peaks observed around the temperatures of degradation of the acids and the thermally induced chemical reactions between products of acid degradation and freshly formed surfaces of aluminum particles. The release of heat in the mixtures begins at 30-40°C. The thermal effects in the mixtures of different acids change according to the order of acid reactivity in solutions. The extreme baric dependences of enthalpies of thermal effects are associated with the rearrangement of the electron subsystem of aluminum upon plastic deformation at high pressures.

Investigation of concrete mixtures incorporating hollow plastic microspheres.

DOT National Transportation Integrated Search

1981-01-01

This study investigated the potential of hollow plastic microspheres, HPM, for providing non-air-entrained portland cement concrete resistance to damage from cycles of freezing and thawing. In the study, a mixture with an air-entraining agent (vinsol...

Ingested plastic transfers hazardous chemicals to fish and induces hepatic stress

PubMed Central

Rochman, Chelsea M.; Hoh, Eunha; Kurobe, Tomofumi; Teh, Swee J.

2013-01-01

Plastic debris litters aquatic habitats globally, the majority of which is microscopic (< 1 mm), and is ingested by a large range of species. Risks associated with such small fragments come from the material itself and from chemical pollutants that sorb to it from surrounding water. Hazards associated with the complex mixture of plastic and accumulated pollutants are largely unknown. Here, we show that fish, exposed to a mixture of polyethylene with chemical pollutants sorbed from the marine environment, bioaccumulate these chemical pollutants and suffer liver toxicity and pathology. Fish fed virgin polyethylene fragments also show signs of stress, although less severe than fish fed marine polyethylene fragments. We provide baseline information regarding the bioaccumulation of chemicals and associated health effects from plastic ingestion in fish and demonstrate that future assessments should consider the complex mixture of the plastic material and their associated chemical pollutants. PMID:24263561

Tests for Plastic Fines in Aggregates Related to Stripping in Asphalt Paving Mixtures

DOT National Transportation Integrated Search

1988-03-01

This study was undertaken for determining the best aggregate test method that indicates the presence of detrimental plastic fines in the fine aggregate, which may induce stripping in hot mix asphalt (HMA) mixtures. Ten fine aggregates representing a ...

Ultrasonic velocity and absorption study of binary mixtures of cyclohexane with acrylonitrile by interferometric method at different frequencies

NASA Astrophysics Data System (ADS)

Pawar, N. R.; Chimankar, O. P.; Bhandakkar, V. D.; Padole, N. N.

2012-12-01

The ultrasonic velocity (u), absorption (α), density (ρ), and viscosity (η) has been measured at different frequencies (1MHz to 10MHz) in the binary mixtures of cyclohexane with acrylonitriile over the entire range of composition at temperature 303K. Vander Waal's constant (b), adiabatic compressibility (βa), acoustic impedance (Z), molar volume (V), free length (Lf), free volume, internal pressure, intermolecular radius and relative association have been also calculated. A special application for acrylonitrile is in the manufacture of carbon fibers. These are produced by paralysis of oriented poly acrylonitrile fibers and are used to reinforce composites for high-performance applications in the aircraft, defense and aerospace industries. Other applications of acrylonitrile are in the production of fatty amines, ion exchange resins and fatty amine amides used in cosmetics, adhesives, corrosion inhibitors and water-treatment resins. Cyclohexane derivatives can be used for the synthesis of pharmaceuticals, dyes, herbicides, plant growth regulator, plasticizers, rubber chemicals, nylon, cyclamens and other organic compounds. In the view of these extensive applications of acrylonitrile and cyclohexane in the engineering process, textile and pharmaceutical industries present study provides qualitative information regarding the nature and strength of interaction in the liquid mixtures through derive parameters from ultrasonic velocity and absorption measurement.

Evidence on unusual way of cocaine smuggling: cocaine-polymethyl methacrylate (PMMA) solid solution--study of clandestine laboratory samples.

PubMed

Gostic, T; Klemenc, S

2007-07-04

An abandoned clandestine laboratory was seized in Slovenia. All confiscated exhibits were analysed in a forensic laboratory, where the following analytical methods were applied: capillary gas chromatography coupled with mass spectrometry (GC-MS) combined also by solid-phase micro extraction (SPME) and pyrolysis (Py) technique, Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy with energy dispersive X-ray detector (SEM-EDX). The most interesting analytical findings can be summarised as follows: at the crime scene some plastic pieces, which contained cocaine dissolved (as solid solution) in polymethyl methacrylate-plexiglass (PMMA), were found. The highest cocaine concentration measured in the plastic sample was about 15% by weight. Two larger lumps of material (12 and 3 kg) were composed mainly of PMMA and CaCO3 and contained only 0.4 and 0.5% of cocaine, respectively. As for the low cocaine concentration, we assume that those two lumps of material represent discarded waste product--residue after the isolation of cocaine from plastic. Higher quantities of pure solvents (41 l) and solvent mixtures (87 l) were seized. We identified three types of pure solvents (acetone, gasoline and benzine) and two different types of solvent mixtures (benzine/acetone and gasoline/acetone). The total seized volume (87 l) of solvent mixtures holds approximately 395 g of solid residue formed mainly of PMMA and cocaine. Obviously solvent mixtures were used for isolation of cocaine from the plastic. Small quantities of relatively pure cocaine base were identified on different objects. There were two cotton sheets, most probably used for filtration. One sheet had traces of cocaine base (76% purity) on the surface, while cocaine in hydrochloride form (96%) was identified on the other sheet. GC-MS analyses of micro traces isolated from analytical balances showed the presence of cocaine and some common adulterants: phenacetine, lidocaine and procaine. A cocaine sample compressed in the shape of block was also seized. The above analytical findings inferred us to the conclusion that the illicit laboratory was used for the isolation of cocaine from PMMA resin. Further more, analyses confirm that not only isolation but also further manipulation of cocaine, i.e. adulteration/dilution, as well as the formation of cocaine blocks took place in the house. The information obtained through analyses also allowed us to make some hypotheses about possible multistage isolation procedure.

Production of an alternative fuel by the co-pyrolysis of landfill recovered plastic wastes and used lubrication oils.

PubMed

Breyer, Sacha; Mekhitarian, Loucine; Rimez, Bart; Haut, B

2017-02-01

This work is a preliminary study for the development of a co-pyrolysis process of plastic wastes excavated from a landfill and used lubrication oils, with the aim to produce an alternative liquid fuel for industrial use. First, thermogravimetric experiments were carried out with pure plastics (HDPE, LDPE, PP and PS) and oils (a motor oil and a mixture of used lubrication oils) in order to highlight the interactions occurring between a plastic and an oil during their co-pyrolysis. It appears that the main decomposition event of each component takes place at higher temperatures when the components are mixed than when they are alone, possibly because the two components stabilize each other during their co-pyrolysis. These interactions depend on the nature of the plastic and the oil. In addition, co-pyrolysis experiments were led in a lab-scale reactor using a mixture of excavated plastic wastes and used lubrication oils. On the one hand, the influence of some key operating parameters on the outcome of the process was analyzed. It was possible to produce an alternative fuel for industrial use whose viscosity is lower than 1Pas at 90°C, from a plastic/oil mixture with an initial plastic mass fraction between 40% and 60%, by proceeding at a maximum temperature included in the range 350-400°C. On the other hand, the amount of energy required to successfully co-pyrolyze, in lab conditions, 1kg of plastic/oil mixture with an initial plastic mass fraction of 60% was estimated at about 8MJ. That amount of energy is largely used for the thermal cracking of the molecules. It is also shown that, per kg of mixture introduced in the lab reactor, 29MJ can be recovered from the combustion of the liquid resulting from the co-pyrolysis. Hence, this co-pyrolysis process could be economically viable, provided heat losses are addressed carefully when designing an industrial reactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Numerical analysis of wet separation of particles by density differences

NASA Astrophysics Data System (ADS)

Markauskas, D.; Kruggel-Emden, H.

2017-07-01

Wet particle separation is widely used in mineral processing and plastic recycling to separate mixtures of particulate materials into further usable fractions due to density differences. This work presents efforts aiming to numerically analyze the wet separation of particles with different densities. In the current study the discrete element method (DEM) is used for the solid phase while the smoothed particle hydrodynamics (SPH) is used for modeling of the liquid phase. The two phases are coupled by the use of a volume averaging technique. In the current study, simulations of spherical particle separation were performed. In these simulations, a set of generated particles with two different densities is dropped into a rectangular container filled with liquid. The results of simulations with two different mixtures of particles demonstrated how separation depends on the densities of particles.

Anaerobic digestion of municipal solid waste composed of food waste, wastepaper, and plastic in a single-stage system: performance and microbial community structure characterization.

PubMed

Wan, Shungang; Sun, Lei; Douieb, Yaniv; Sun, Jian; Luo, Wensui

2013-10-01

The performance of municipal organic solid waste anaerobic digestion was investigated using a single-stage bioreactor, and the microbial community structures were characterized during the digestion. The results showed that the biogas and methane production rates were 592.4 and 370.1L/kg with volatile solid added at the ratio of 2:1:1 for food waste, wastepaper, and plastic based on dry weight. The methane volume concentration fluctuated between 44.3% and 75.4% at steady stage. Acetic acid, propionic acid, and butyric acid were the major volatile fatty acids produced during the digestion process. The anaerobic process was not inhibited by the accumulation of ammonia and free ammonia. The bacterial community was found to consist of at least 21 bands of bacteria and 12 bands of archaea at the steady state. All of the results indicated that the mixture of food waste, wastepaper, and plastic could be efficiently co-digested using the anaerobic digestion system. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Effects of different excipients on properties of Tongsaimai mixture and pellet molding].

PubMed

Wang, Jin; Lv, Zhiyang; Wu, Xiaoyan; Di, Liuqing; Dong, Yu; Cai, Baochang

2011-01-01

To study preliminarily on the relationship between properties of the mixture composed of Tongsaimai extract and different excipients and pellet molding. The multivariate regression analysis was used to investigate the correlation of different mixture and pellet molding by measuring the cohesion, liquid-plastic limit of mixture, and the powder properties of pellets. The weighted coefficients of the powder properties were determined by analytic hierarchy process combined with criteria importance through intercriteria correlation. The results showed that liquid-plastic limit seemed to be a major factor, which had positive correlation with pellet molding, while cohesion had negative correlation with pellet molding in the measured range. The physical properties of the mixture has marked influence on pellet molding.

Innovative plasticized alginate obtained by thermo-mechanical mixing: Effect of different biobased polyols systems.

PubMed

Gao, Chengcheng; Pollet, Eric; Avérous, Luc

2017-02-10

Plasticized alginate films with different biobased polyols (glycerol and sorbitol) and their mixtures were successfully prepared by thermo-mechanical mixing instead of the usual casting-evaporation procedure. The microstructure and properties of the different plasticized alginate formulations were investigated by SEM, FTIR, XRD, DMTA and uniaxial tensile tests. SEM and XRD results showed that native alginate particles were largely destructured with the plasticizers (polyols and water), under a thermo-mechanical input. With increasing amount of plasticizers, the samples showed enhanced homogeneity while their thermal and mechanical properties decreased. Compared to sorbitol, glycerol resulted in alginate films with a higher flexibility due to its better plasticization efficiency resulting from its smaller size and higher hydrophilic character. Glycerol and sorbitol mixtures seemed to be an optimum to obtain the best properties. This work showed that thermo-mechanical mixing is a promising method to produce, at large scale, plasticized alginate-based films with improved properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multicomponent membranes

DOEpatents

Kulprathipanja, Santi; Kulkarni, Sudhir S.; Funk, Edward W.

1988-01-01

A multicomponent membrane which may be used for separating various components which are present in a fluid feed mixture comprises a mixture of a plasticizer such as a glycol and an organic polymer cast upon a porous organic polymer support. The membrane may be prepared by casting an emulsion or a solution of the plasticizer and polymer on the porous support, evaporating the solvent and recovering the membrane after curing.

Peculiarities of methane clathrate hydrate formation and solid-state deformation, including possible superheating of water ice

USGS Publications Warehouse

Stern, L.A.; Kirby, S.H.; Durham, W.B.

1996-01-01

Slow, constant-volume heating of water ice plus methane gas mixtures forms methane clathrate hydrate by a progressive reaction that occurs at the nascent ice/liquid water interface. As this reaction proceeds, the rate of melting of metastable water ice may be suppressed to allow short-lived superheating of ice to at least 276 kelvin. Plastic flow properties measured on clathrate test specimens are significantly different from those of water ice; under nonhydrostatic stress, methane clathrate undergoes extensive strain hardening and a process of solid-state disproportionation or exsolution at conditions well within its conventional hydrostatic stability field.

Utilization of polyethylene terephthalate (PET) in asphalt pavement: A review

NASA Astrophysics Data System (ADS)

Ahmad, A. F.; Razali, A. R.; Razelan, I. S. M.

2017-05-01

The quantity of plastics used throughout the world is increasing every year. Municipal solid wastes (MSW), manufacturing processes and service industries produce a lot of waste plastic materials. The increasing awareness among consumers about the environment has contributed to the concerns over disposal of generated wastes. The growing number of plastic materials every year and limited landfill conditions causes many alternatives exist for the disposal of plastic waste. This paper provides a summary of the study on the utilization of polyethylene terephthalate (PET) in road construction. Data from researcher show that PET can improve some properties of modified asphalt mixture. Having considered the economic and environmental prudent angles, utilization of PET as an additive to asphalt mixture is suitable to be used for road pavement.

Production and delivery of a fluid mixture to an annular volume of a wellbore

DOEpatents

Hermes, Robert E [Los Alamos, NM; Bland, Ronald Gene [Houston, TX; Foley, Ron Lee [Magnolia, TX; Bloys, James B [Katy, TX; Gonzalez, Manuel E [Kingwood, NM; Daniel, John M [Germantown, TN; Robinson, Ian M [Guisborough, GB; Carpenter, Robert B [Tomball, TX

2012-01-24

The methods described herein generally relate to preparing and delivering a fluid mixture to a confined volume, specifically an annular volume located between two concentrically oriented casing strings within a hydrocarbon fluid producing well. The fluid mixtures disclosed herein are useful in controlling pressure in localized volumes. The fluid mixtures comprise at least one polymerizable monomer and at least one inhibitor. The processes and methods disclosed herein allow the fluid mixture to be stored, shipped and/or injected into localized volumes, for example, an annular volume defined by concentric well casing strings.

Understanding deformation mechanisms during powder compaction using principal component analysis of compression data.

PubMed

Roopwani, Rahul; Buckner, Ira S

2011-10-14

Principal component analysis (PCA) was applied to pharmaceutical powder compaction. A solid fraction parameter (SF(c/d)) and a mechanical work parameter (W(c/d)) representing irreversible compression behavior were determined as functions of applied load. Multivariate analysis of the compression data was carried out using PCA. The first principal component (PC1) showed loadings for the solid fraction and work values that agreed with changes in the relative significance of plastic deformation to consolidation at different pressures. The PC1 scores showed the same rank order as the relative plasticity ranking derived from the literature for common pharmaceutical materials. The utility of PC1 in understanding deformation was extended to binary mixtures using a subset of the original materials. Combinations of brittle and plastic materials were characterized using the PCA method. The relationships between PC1 scores and the weight fractions of the mixtures were typically linear showing ideal mixing in their deformation behaviors. The mixture consisting of two plastic materials was the only combination to show a consistent positive deviation from ideality. The application of PCA to solid fraction and mechanical work data appears to be an effective means of predicting deformation behavior during compaction of simple powder mixtures. Copyright © 2011 Elsevier B.V. All rights reserved.

Characterization and evaluation physical properties biodegradable plastic composite from seaweed (Eucheuma cottonii)

NASA Astrophysics Data System (ADS)

Deni, Glar Donia; Dhaningtyas, Shalihat Afifah; Fajar, Ibnu; Sudarno

2015-12-01

The characterization and evaluation of biodegradable plastic composed of a mixture PVA - carrageenan - chitosan was conducted in this study. Obtained data were then compared to commercial biodegradable plastic. Characteristic of plastic was mechanical tested such as tensile - strength and elongation. Plastic degradation was studied using composting method for 7 days and 14 days. The results showed that the increase carrageenan will decrease tensile-strength and elongation plastic composite. In addition, increase carrageenan would increase the degraded plastics composite.

Biodegradable packaging materials conception based on starch and polylactic acid (PLA) reinforced with cellulose.

PubMed

Masmoudi, Fatma; Bessadok, Atef; Dammak, Mohamed; Jaziri, Mohamed; Ammar, Emna

2016-10-01

The plastic materials used for packaging are increasing leading to a considerable amount of undegradable solid wastes. This work deals with the reduction of conventional plastics waste and the natural resources preservation by using cellulosic polymers from renewable resources (alfa and luffa). Plasticized starch films syntheses were achieved at a laboratory scale. These natural films showed some very attractive mechanical properties at relatively low plasticizers levels (12 to 17 % by weight). Furthermore, mixtures including polylactic acid polymer (PLA) and cellulose fibers extracted from alfa and luffa were investigated by melt extrusion technique. When used at a rate of 10 %, these fibers improved the mixture mechanical properties. Both developed materials were biodegradable, but the plasticized starch exhibited a faster biodegradation kinetic compared to the PLA/cellulose fibers. These new materials would contribute to a sustainable development and a waste reduction.

H-ZSM5 Catalyzed co-pyrolysis of biomass and plastics

USDA-ARS?s Scientific Manuscript database

This study aims at addressing two important problems vital to agriculture, disposal of agricultural plastics and production of drop-in fuels from biomass via co-pyrolysis of both feedstocks. Mixtures of biomass (switchgrass, cellulose, xylan and lignin) and plastic (polyethylene terephthalate (PET),...

Biodegradation of Polyethylene and Plastic Mixtures in Mealworms (Larvae of Tenebrio molitor) and Effects on the Gut Microbiome.

PubMed

Brandon, Anja Malawi; Gao, Shu-Hong; Tian, Renmao; Ning, Daliang; Yang, Shan-Shan; Zhou, Jizhong; Wu, Wei-Min; Criddle, Craig S

2018-06-05

Recent studies have demonstrated the ability for polystyrene (PS) degradation within the gut of mealworms ( Tenebrio molitor). To determine whether plastics may be broadly susceptible to biodegradation within mealworms, we evaluated the fate of polyethylene (PE) and mixtures (PE + PS). We find that PE biodegrades at comparable rates to PS. Mass balances indicate conversion of up 49.0 ± 1.4% of the ingested PE into a putative gas fraction (CO 2 ). The molecular weights ( M n ) of egested polymer residues decreased by 40.1 ± 8.5% in PE-fed mealworms and by 12.8 ± 3.1% in PS-fed mealworms. NMR and FTIR analyses revealed chemical modifications consistent with degradation and partial oxidation of the polymer. Mixtures likewise degraded. Our results are consistent with a nonspecific degradation mechanism. Analysis of the gut microbiome by next-generation sequencing revealed two OTUs ( Citrobacter sp. and Kosakonia sp.) strongly associated with both PE and PS as well as OTUs unique to each plastic. Our results suggest that adaptability of the mealworm gut microbiome enables degradation of chemically dissimilar plastics.

Methods for the continuous production of plastic scintillator materials

DOEpatents

Bross, Alan; Pla-Dalmau, Anna; Mellott, Kerry

1999-10-19

Methods for producing plastic scintillating material employing either two major steps (tumble-mix) or a single major step (inline-coloring or inline-doping). Using the two step method, the polymer pellets are mixed with silicone oil, and the mixture is then tumble mixed with the dopants necessary to yield the proper response from the scintillator material. The mixture is then placed in a compounder and compounded in an inert gas atmosphere. The resultant scintillator material is then extruded and pelletized or formed. When only a single step is employed, the polymer pellets and dopants are metered into an inline-coloring extruding system. The mixture is then processed under a inert gas atmosphere, usually argon or nitrogen, to form plastic scintillator material in the form of either scintillator pellets, for subsequent processing, or as material in the direct formation of the final scintillator shape or form.

Investigation of Expedient Ground Surfacing with a Glass Fiber-Resin Mixture by a Spray-Deposition Technique,

DTIC Science & Technology

PAVEMENTS, *REINFORCED PLASTICS), LANDING FIELDS, SPRAYS, GLASS TEXTILES, LAMINATED PLASTICS, TEST METHODS, FOUNDATIONS(STRUCTURES), SANDWICH CONSTRUCTION, SOILS, FEASIBILITY STUDIES, LOAD DISTRIBUTION

Hydraulic separation of plastic wastes: Analysis of liquid-solid interaction.

PubMed

Moroni, Monica; Lupo, Emanuela; La Marca, Floriana

2017-08-01

The separation of plastic wastes in mechanical recycling plants is the process that ensures high-quality secondary raw materials. An innovative device employing a wet technology for particle separation is presented in this work. Due to the combination of the characteristic flow pattern developing within the apparatus and density, shape and size differences among two or more polymers, it allows their separation into two products, one collected within the instrument and the other one expelled through its outlet ducts. The kinematic investigation of the fluid flowing within the apparatus seeded with a passive tracer was conducted via image analysis for different hydraulic configurations. The two-dimensional turbulent kinetic energy results strictly connected to the apparatus separation efficacy. Image analysis was also employed to study the behaviour of mixtures of passive tracer and plastic particles with different physical characteristics in order to understand the coupling regime between fluid and solid phases. The two-dimensional turbulent kinetic energy analysis turned out to be fundamental to this aim. For the tested operating conditions, two-way coupling takes place, i.e., the fluid exerts an influence on the plastic particle and the opposite occurs too. Image analysis confirms the outcomes from the investigation of the two-phase flow via non-dimensional numbers (particle Reynolds number, Stokes number and solid phase volume fraction). Copyright © 2017 Elsevier Ltd. All rights reserved.

Sol-gel antireflective coating on plastics

DOEpatents

Ashley, C.S.; Reed, S.T.

1988-01-26

An antireflection film made from reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

Sol-gel antireflective coating on plastics

DOEpatents

Ashley, Carol S.; Reed, Scott T.

1990-01-01

An antireflection film made from a reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

Characterization and Separation of Cancer Cells with a Wicking Fiber Device.

PubMed

Tabbaa, Suzanne M; Sharp, Julia L; Burg, Karen J L

2017-12-01

Current cancer diagnostic methods lack the ability to quickly, simply, efficiently, and inexpensively screen cancer cells from a mixed population of cancer and normal cells. Methods based on biomarkers are unreliable due to complexity of cancer cells, plasticity of markers, and lack of common tumorigenic markers. Diagnostics are time intensive, require multiple tests, and provide limited information. In this study, we developed a novel wicking fiber device that separates cancer and normal cell types. To the best of our knowledge, no previous work has used vertical wicking of cells through fibers to identify and isolate cancer cells. The device separated mouse mammary tumor cells from a cellular mixture containing normal mouse mammary cells. Further investigation showed the device separated and isolated human cancer cells from a heterogeneous mixture of normal and cancerous human cells. We report a simple, inexpensive, and rapid technique that has potential to identify and isolate cancer cells from large volumes of liquid samples that can be translated to on-site clinic diagnosis.

Evaluation of tableting and tablet properties of Kollidon SR: the influence of moisture and mixtures with theophylline monohydrate.

PubMed

Hauschild, Karsten; Picker-Freyer, Katharina M

2006-02-01

The aim of the study was firstly to investigate the influence of moisture on the tableting and tablet properties of Kollidon SR and secondly to investigate the influence of theophylline monohydrate on the tableting behavior and tablet properties produced from binary mixtures with Kollidon SR. In comparison to Kollidon SR, microcrystalline cellulose (MCC) was used. The glass transition temperature (Tg) of the powder over the whole range of RH (0-90%), and in addition, the Tg of tablets of Kollidon SR were measured. Densities and flowability of the powders were analyzed. The tablets were produced at five different maximum relative densities (rho(rel), max) on an instrumented eccentric tableting machine. They were produced at three different relative humidities (RH), 30%, 45%, and 60% RH for the pure substances and binary mixtures with different ratios of drug and excipient were tableted at 45% RH. The tableting properties were analyzed by 3D modeling, force-displacement profiles, and compactibility plots. First, the Tg of the powder decreased with increasing RH and the Tg of the tablet was 4-8 K lower than the powder. The predominant deformation of Kollidon SR is plastic deformation and Kollidon SR showed a higher compactibility than MCC. The parameters of the 3D model showed an extreme change between 45 and 60% RH, and at higher RH more and more particles deformed elastically. This was confirmed by analysis of force-displacement profiles. At 60% RH, the radial tensile strength of the Kollidon SR tablets was half of the radial tensile strength at 45% RH. The reason is a higher relative energy of plastic deformation than for MCC. This results in a better utilization of the energy to deform the powder into a tablet and the exceeding of the glass transition temperature at higher RH. In conclusion, at 60% RH at the same rho(rel, max), tableting and tablet properties of Kollidon SR are extremely changed since plasticity is significantly higher. In the second part of the study, the insufficient flowability of theophylline monohydrate can be compensated by using Kollidon SR in a mixture with up to 20% theophylline. Further, pressure plasticity e of MCC and Kollidon SR was lowered in the mixture with theophylline monohydrate. The same is valid for the compactibility. The influence of theophylline monohydrate on the pressure plasticity e of the mixtures was better compensated in the mixture with MCC than in a mixture with Kollidon SR. This compensation was also visible by analyzing the force-displacement-profiles. However, hardly any influence on the radial tensile strength could be detected. Kollidon SR and Kollidon SR mixtures exhibited a higher compactibility than MCC and MCC mixtures. The differences became smaller with increasing theophylline content.

Thermogravimetric and calorimetric characteristics during co-pyrolysis of municipal solid waste components.

PubMed

Ansah, Emmanuel; Wang, Lijun; Shahbazi, Abolghasem

2016-10-01

The thermogravimetric and calorimetric characteristics during pyrolysis of wood, paper, textile and polyethylene terephthalate (PET) plastic in municipal solid wastes (MSW), and co-pyrolysis of biomass-derived and plastic components with and without torrefaction were investigated. The active pyrolysis of the PET plastic occurred at a much higher temperature range between 360°C and 480°C than 220-380°C for the biomass derived components. The plastic pyrolyzed at a heating rate of 10°C/min had the highest maximum weight loss rate of 18.5wt%/min occurred at 420°C, followed by 10.8wt%/min at 340°C for both paper and textile, and 9.9wt%/min at 360°C for wood. At the end of the active pyrolysis stage, the final mass of paper, wood, textile and PET was 28.77%, 26.78%, 21.62% and 18.31%, respectively. During pyrolysis of individual MSW components at 500°C, the wood required the least amount of heat at 665.2J/g, compared to 2483.2J/g for textile, 2059.4J/g for paper and 2256.1J/g for PET plastic. The PET plastic had much higher activation energy of 181.86kJ/mol, compared to 41.47kJ/mol for wood, 50.01kJ/mol for paper and 36.65kJ/mol for textile during pyrolysis at a heating rate of 10°C/min. H2O and H2 peaks were observed on the MS curves for the pyrolysis of three biomass-derived materials but there was no obvious H2O and H2 peaks on the MS curves of PET plastic. There was a significant interaction between biomass and PET plastic during co-pyrolysis if the biomass fraction was dominant. The amount of heat required for the co-pyrolysis of the biomass and plastic mixture increased with the increase of plastic mass fraction in the mixture. Torrefaction at a proper temperature and time could improve the grindability of PET plastic. The increase of torrefaction temperature and time did not affect the temperature where the maximum pyrolytic rates occurred for both biomass and plastic but decreased the maximum pyrolysis rate of biomass and increased the maximum pyrolysis rate of PET plastic. The amount of heat for the pyrolysis of biomass and PET mixture co-torrefied at 280°C for 30min was 4365J/g at 500°C, compared to 1138J/g for the pyrolysis of raw 50% wood and 50% PET mixture at the same condition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Separation of polycarbonate and acrylonitrile–butadiene–styrene waste plastics by froth flotation combined with ammonia pretreatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chong-qing; Wang, Hui, E-mail: huiwang1968@163.com; Liu, Qun

Highlights: • Ammonia treatment changes selectively floatability of PC. • The effects of ammonia on PC were investigated through contact angle and XPS. • Reactions between ammonia and PC surface make PC more hydrophilic. • PC and ABS mixtures with different particle sizes were separated effectively. - Abstract: The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile–butadiene–styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping ofmore » flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability.« less

Experience-driven plasticity in binocular vision

PubMed Central

Klink, P. Christiaan; Brascamp, Jan W.; Blake, Randolph; van Wezel, Richard J.A.

2010-01-01

Summary Experience-driven neuronal plasticity allows the brain to adapt its functional connectivity to recent sensory input. Here we use binocular rivalry [1], an experimental paradigm where conflicting images are presented to the individual eyes, to demonstrate plasticity in the neuronal mechanisms that convert visual information from two separated retinas into single perceptual experiences. Perception during binocular rivalry tended to initially consist of alternations between exclusive representations of monocularly defined images, but upon prolonged exposure, mixture percepts became more prevalent. The completeness of suppression, reflected in the incidence of mixture percepts, plausibly reflects the strength of inhibition that likely plays a role in binocular rivalry [2]. Recovery of exclusivity was possible, but required highly specific binocular stimulation. Documenting the prerequisites for these observed changes in perceptual exclusivity, our experiments suggest experience-driven plasticity at interocular inhibitory synapses, driven by the (lack of) correlated activity of neurons representing the conflicting stimuli. This form of plasticity is consistent with a previously proposed, but largely untested, anti-Hebbian learning mechanism for inhibitory synapses in vision [3, 4]. Our results implicate experience-driven plasticity as one governing principle in the neuronal organization of binocular vision. PMID:20674360

Correlating the cold flow and melting properties of fatty acid methyl ester (FAME) mixtures

USDA-ARS?s Scientific Manuscript database

Fatty acid methyl ester (FAME) mixtures derived from plant oils or animal fats are used to make biodiesel, lubricants, surfactants, plasticizers, ink solvents, paint strippers and other products. Processing requires a precise knowledge of the physico-chemical properties of mixtures with diverse and ...

Influence of deformation on structural-phase state of weld material in St3 steel

NASA Astrophysics Data System (ADS)

Smirnov, Alexander; Kozlov, Eduard; Ababkov, Nicolay; Popova, Natalya; Nikonenko, Elena; Ozhiganov, Yevgeniy; Zboykova, Nadezhda; Koneva, Nina

2016-01-01

The structural-phase condition of the weld material subjected to the plastic deformation was investigated using the translucent diffraction electron microscopy method. The investigations were carried out near the joint of the weld and the base metal. The seam was done by the method of manual arc welding without artificial defects. The St3 steel was taken as the welded material. Influence of the plastic deformation on morphology, phase composition, defect structure and its parameters of weld metal was revealed. All investigations were done at the distance of 0.5 mm from the joint of the weld and the base metal at the deformation degrees from 0 to 5% and after destruction of a sample. It was established that deformation of the sample did not lead to qualitative changes in the structure (the structure is still presented by ferrite-pearlite mixture) but changed the quantitative parameters of the structure, namely, with the increase of plastic deformation a part of the pearlite component becomes more and more imperfect. In the beginning it turns into the destroyed pearlite then into ferrite, the volume fraction of pearlite is decreased. The polarization of dislocation structure takes place but it doesn't lead to the internal stresses that can destroy the sample.

Theoretical and numerical aspects of fluid-saturated elasto-plastic soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ehlers, W.

1995-12-31

The theoretical and numerical treatment of fluid-saturated porous solid materials generally falls into the category of porous media models, which are described within the framework of the classical theory of mixtures extended by the concept of volume fractions (porous media theories). In particular, this concept allows for the description of saturated, unsaturated and empty porous matrix materials, thus offering a well-founded theoretical background for a lot of engineering problems occurring, for instance, in the fields of geomechanics (soil and rock mechanics as well as glacier and rock ice mechanics), oil producing industries, sintering technologies, biomechanics, etc. In the present contribution,more » theoretical and numerical studies are outlined to describe a two-phase material composed of an incompressible elasto-plastic soil matrix saturated by an incompressible viscous pore fluid. In this context, the phenomenon of phase incompressibility is well known as a microscopic effect not implying bulk incompressibility in the macro regime. This is seen from the fact that even if the material density functions of the individual constituents are constant during deformation, the corresponding bulk densities can still change through changes in the volume fractions. Within the framework of a pure mechanical theory, constitutive equations are given for both the solid and the fluid partial stress tensors and for the interaction force acting between the two materials. Concerning the porous soil matrix, the elastic properties are described by an elasticity law of Hookean type, while the plastic range is governed by a {open_quote}single surface{close_quote} yield function exhibiting a smooth and closed shape in the principal stress space together with a non-associated flow rule. The viscosity effects of the pore fluid are included in the fluid stress tensor and in the drag force.« less

Synthesis and Characterization of Diglycerol Tetranitrate (DGTN)—An Energetic Plasticizer for Use in Explosive and Propellant Formulations

NASA Astrophysics Data System (ADS)

Straessler, Nicholas; Lee, Manfai

2017-01-01

Diglycerol was nitrated using mixed acid conditions to give diglycerol tetranitrate and related coproducts. The product mixture was extracted in situ with methylene chloride and analyzed by 1H- and 13C-NMR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and high-performance liquid chromatography-mass spectrometry (HPLC-MS). Results showed that the product mixture was a combination of two isomers of diglycerol tetranitrate, triglycerol pentanitrate, cyclotriglycerol trinitrate, and diglycerol trinitrate. The mixture of products is explained by the composition of the starting material and by associated side reactions that occur during nitration. This synthesis and analytical data will aid in better understanding diglycerol tetranitrate as a plasticizer in explosive and propellant formulations.

Computational material design for Q&P steels with plastic instability theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, G.; Choi, K. S.; Hu, X. H.

In this paper, the deformation limits of Quenching and Partitioning (Q&P) steels are examined with the plastic instability theory. For this purpose, the constituent phase properties of various Q&P steels were first experimentally obtained, and used to estimate the overall tensile stress-strain curves based on the simple rule of mixture (ROM) with the iso-strain and iso-stress assumptions. Plastic instability theory was then applied to the obtained overall stress-strain curves in order to estimate the deformation limits of the Q&P steels. A parametric study was also performed to examine the effects of various material parameters on the deformation limits of Q&Pmore » steels. Computational material design was subsequently carried out based on the information obtained from the parametric study. The results show that the plastic instability theory with iso-stress-based stress-strain curve may be used to provide the lower bound estimate of the uniform elongation (UE) for the various Q&P steels considered. The results also indicate that higher austenite stability/volume fractions, less strength difference between the primary phases, higher hardening exponents of the constituent phases are generally beneficial for the performance improvement of Q&P steels, and that various material parameters may be concurrently adjusted in a cohesive way in order to improve the performance of Q&P steel. The information from this study may be used to devise new heat treatment parameters and alloying elements to produce Q&P steels with the improved performance.« less

Separation of mixed waste plastics via magnetic levitation.

PubMed

Zhao, Peng; Xie, Jun; Gu, Fu; Sharmin, Nusrat; Hall, Philip; Fu, Jianzhong

2018-06-01

Separation becomes a bottleneck of dealing with the enormous stream of waste plastics, as most of the extant methods can only handle binary mixtures. In this paper, a novel method that based on magnetic levitation was proposed for separating multiple mixed plastics. Six types of plastics, i.e., polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyamide 6 (PA6), polycarbonate (PC), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE), were used to simulate the mixed waste plastics. The samples were mixed and immersed into paramagnetic medium that placed into a magnetic levitation configuration with two identical NdFeB magnets with like-poles facing each other, and Fourier transform infrared (FTIR) spectroscopy was employed to verify the separation outputs. Unlike any conventional separation methods such as froth flotation and hydrocyclone, this method is not limited by particle sizes, as mixtures of different size fractions reached their respective equilibrium positions in the initial tests. The two-stage separation tests demonstrated that the plastics can be completely separated with purities reached 100%. The method has the potential to be industrialised into an economically-viable and environmentally-friendly mass production procedure, since quantitative correlations are determined, and the paramagnetic medium can be reused indefinitely. Copyright © 2018 Elsevier Ltd. All rights reserved.

Separation of polycarbonate and acrylonitrile-butadiene-styrene waste plastics by froth flotation combined with ammonia pretreatment.

PubMed

Wang, Chong-Qing; Wang, Hui; Liu, Qun; Fu, Jian-Gang; Liu, You-Nian

2014-12-01

The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of milling on the plastic and the elastic stiffness of lactose particles.

PubMed

Pazesh, Samaneh; Persson, Ann-Sofie; Berggren, Jonas; Alderborn, Göran

2018-03-01

The purpose of this study was to investigate the effect of degree of disorder of a series of α-lactose monohydrate powders, prepared by milling for different time periods, on the plastic and the elastic stiffness of the particles. As references, a series of physical mixtures consisting of original crystalline particles and amorphous particles obtained by spray-drying was used. In addition, the effect of powder pre-storage humidity on the mechanical properties was investigated. For milled particles of a low degree of disorder, a decreased particle size increased the particle plastic stiffness. For milled particles of constant particle size, the plastic stiffness decreased with an increased degree of disorder while the elastic stiffness seemed nearly independent of the degree of disorder. The presence of moisture caused a recrystallisation of milled particles with low degree of disorder which increased their plastic stiffness. For the physical mixtures of crystalline and amorphous particles, similar relationships between plastic stiffness and amorphous content as for the milled powders were obtained. A reasonable explanation is that the nature of the milled particles is represented by a two-state system with crystalline and amorphous domains. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Experimental investigation of thermodynamic properties of binary mixture of acetic acid + n-butanol and acetic acid + water at temperature from 293.15 K to 343.15 K

NASA Astrophysics Data System (ADS)

Paul, M. Danish John; Shruthi, N.; Anantharaj, R.

2018-04-01

The derived thermodynamic properties like excess molar volume, partial molar volume, excess partial molar volume and apparent volume of binary mixture of acetic acid + n-butanolandacetic acid + water has been investigated using measured density of mixtures at temperatures from 293.15 K to 343.15.

Density of Asphalt Concrete - How Much is Needed?

DOT National Transportation Integrated Search

1990-01-01

Density is one of the most important parameters in construction of asphalt : mixtures. A mixture that is properly designed and compacted will contain enough : air voids to prevent rutting due to plastic flow but low enough air voids to : prevent perm...

Plastics Derived Endocrine Disruptors (BPA, DEHP and DBP) Induce Epigenetic Transgenerational Inheritance of Obesity, Reproductive Disease and Sperm Epimutations

PubMed Central

Manikkam, Mohan; Tracey, Rebecca; Guerrero-Bosagna, Carlos; Skinner, Michael K.

2013-01-01

Environmental compounds are known to promote epigenetic transgenerational inheritance of adult onset disease in subsequent generations (F1–F3) following ancestral exposure during fetal gonadal sex determination. The current study was designed to determine if a mixture of plastic derived endocrine disruptor compounds bisphenol-A (BPA), bis(2-ethylhexyl)phthalate (DEHP) and dibutyl phthalate (DBP) at two different doses promoted epigenetic transgenerational inheritance of adult onset disease and associated DNA methylation epimutations in sperm. Gestating F0 generation females were exposed to either the “plastics” or “lower dose plastics” mixture during embryonic days 8 to 14 of gonadal sex determination and the incidence of adult onset disease was evaluated in F1 and F3 generation rats. There were significant increases in the incidence of total disease/abnormalities in F1 and F3 generation male and female animals from plastics lineages. Pubertal abnormalities, testis disease, obesity, and ovarian disease (primary ovarian insufficiency and polycystic ovaries) were increased in the F3 generation animals. Kidney and prostate disease were only observed in the direct fetally exposed F1 generation plastic lineage animals. Analysis of the plastics lineage F3 generation sperm epigenome previously identified 197 differential DNA methylation regions (DMR) in gene promoters, termed epimutations. A number of these transgenerational DMR form a unique direct connection gene network and have previously been shown to correlate with the pathologies identified. Observations demonstrate that a mixture of plastic derived compounds, BPA and phthalates, can promote epigenetic transgenerational inheritance of adult onset disease. The sperm DMR provide potential epigenetic biomarkers for transgenerational disease and/or ancestral environmental exposures. PMID:23359474

The degradability of biodegradable plastics in aerobic and anaerobic waste landfill model reactors.

PubMed

Ishigaki, Tomonori; Sugano, Wataru; Nakanishi, Akane; Tateda, Masafumi; Ike, Michihiko; Fujita, Masanori

2004-01-01

Degradabilities of four kinds of commercial biodegradable plastics (BPs), polyhydroxybutyrate and hydroxyvalerate (PHBV) plastic, polycaprolactone plastic (PCL), blend of starch and polyvinyl alcohol (SPVA) plastic and cellulose acetate (CA) plastic were investigated in waste landfill model reactors that were operated as anaerobically and aerobically. The application of forced aeration to the landfill reactor for supplying aerobic condition could potentially stimulate polymer-degrading microorganisms. However, the individual degradation behavior of BPs under the aerobic condition was completely different. PCL, a chemically synthesized BP, showed film breakage under the both conditions, which may have contributed to a reduction in the waste volume regardless of aerobic or anaerobic conditions. Effective degradation of PHBV plastic was observed in the aerobic condition, though insufficient degradation was observed in the anaerobic condition. But the aeration did not contribute much to accelerate the volume reduction of SPVA plastic and CA plastic. It could be said that the recalcitrant portions of the plastics such as polyvinyl alcohol in SPVA plastic and the highly substituted CA in CA plastic prevented the BP from degradation. These results indicated existence of the great variations in the degradability of BPs in aerobic and anaerobic waste landfills, and suggest that suitable technologies for managing the waste landfill must be combined with utilization of BPs in order to enhance the reduction of waste volume in landfill sites.

Competitive sorption of persistent organic pollutants onto microplastics in the marine environment.

PubMed

Bakir, Adil; Rowland, Steven J; Thompson, Richard C

2012-12-01

Plastics are known to sorb persistent organic pollutants from seawater. However, studies to quantify sorption rates have only considered the affinity of chemicals in isolation, unlike the conditions in the environment where contaminants are present as complex mixtures. Here we examine whether phenanthrene and 4,4'-DDT, in a mixture, compete for sorption sites onto PVC with no added additives (unplasticised PVC or uPVC) and Ultra-High Molecular Weight polyethylene. Interactions were investigated by exposing particles of uPVC and UHMW PE to mixtures of 3H and 14C radiolabelled Phe and DDT. Changes in sorption capacity were modelled by applying a Freundlich binding sorption isotherms. An Extended Langmuir Model and an Interaction Factor Model were also applied to predict equilibrium concentrations of pollutants onto plastic. This study showed that in a bi-solute system, DDT exhibited no significantly different sorption behaviour than in single solute systems. However, DDT did appear to interfere with the sorption of Phe onto plastic, indicating an antagonistic effect. Copyright © 2012 Elsevier Ltd. All rights reserved.

Pyrolysis of virgin and waste polypropylene and its mixtures with waste polyethylene and polystyrene.

PubMed

Kiran Ciliz, Nilgun; Ekinci, Ekrem; Snape, Colin E

2004-01-01

A comparison of waste and virgin polypropylene (PP) plastics under slow pyrolysis conditions is presented. Moreover, mixtures of waste PP with wastes of polyethylene (PE) and polystyrene (PS) were pyrolyzed under the same operating conditions. Not only the impact of waste on degradation products but also impacts of the variations in the mixing ratio were investigated. The thermogravimetric weight loss curves and their derivatives of virgin and waste PP showed differences due to the impurities which are dirt and food residues. The liquid yield distribution concerning the aliphatic, mono-aromatic and poly-aromatic compounds varies as the ratio of PP waste increases in the waste plastic mixtures. In addition to this, the alkene/alkane ratio of gas products shows variations depending on the mixing ratio of wastes.

Hand surgery volume and the US economy: is there a statistical correlation?

PubMed

Gordon, Chad R; Pryor, Landon; Afifi, Ahmed M; Gatherwright, James R; Evans, Peter J; Hendrickson, Mark; Bernard, Steven; Zins, James E

2010-11-01

To the best of our knowledge, there have been no previous studies evaluating the correlation of the US economy and hand surgery volume. Therefore, in light of the current recession, our objective was to study our institution's hand surgery volume over the last 17 years in relation to the nation's economy. A retrospective analysis of our institution's hand surgery volume, as represented by our most common procedure (ie, carpal tunnel release), was performed between January 1992 and October 2008. Liposuction and breast augmentation volumes were chosen to serve as cosmetic plastic surgery comparison groups. Pearson correlation statistics were used to estimate the relationship between the surgical volume and the US economy, as represented by the 3 market indices (Dow Jones, NASDAQ, and S&P500). A combined total of 7884 hand surgery carpal tunnel release (open or endoscopic) patients were identified. There were 1927 (24%) and 5957 (76%) patients within the departments of plastic and orthopedic surgery, respectively. In the plastic surgery department, there was a strong negative (ie, inverse relationship) correlation between hand surgery volume and the economy (P < 0.001). In converse, the orthopedic department's hand surgery volume demonstrated a positive (ie, parallel) correlation (P < 0.001). The volumes of liposuction and breast augmentation also showed a positive correlation (P < 0.001). To our knowledge, we have demonstrated for the first time an inverse (ie, negative) correlation between hand surgery volumes performed by plastic surgeons in relation to the US economy, as represented by the 3 major market indices. In contrast, orthopedic hand surgery volume and cosmetic surgery show a parallel (ie, positive) correlation. This data suggests that plastic surgeons are increasing their cosmetic surgery-to-reconstructive/hand surgery ratio during strong economic times and vice versa during times of economic slowdown.

Canary in a coal mine: does the plastic surgery market predict the american economy?

PubMed

Wong, Wendy W; Davis, Drew G; Son, Andrew K; Camp, Matthew C; Gupta, Subhas C

2010-08-01

Economic tools have been used in the past to predict the trends in plastic surgery procedures. Since 1992, U.S. cosmetic surgery volumes have increased overall, but the exact relationship between economic downturns and procedural volumes remains elusive. If an economic predicting role can be established from plastic surgery indicators, this could prove to be a very powerful tool. A rolling 3-month revenue average of an eight-plastic surgeon practice and various economic indicators were plotted and compared. An investigation of the U.S. procedural volumes was performed from the American Society of Plastic Surgeons statistics between 1996 and 2008. The correlations of different economic variables with plastic surgery volumes were evaluated. Lastly, search term frequencies were examined from 2004 to July of 2009 to study potential patient interest in major plastic surgery procedures. The self-payment revenue of the plastic surgery group consistently proved indicative of the market trends approximately 1 month in advance. The Standard and Poor's 500, Dow Jones Industrial Average, National Association of Securities Dealers Automated Quotations, and Standard and Poor's Retail Index demonstrated a very close relationship with the income of our plastic surgery group. The frequency of Internet search terms showed a constant level of interest in the patient population despite economic downturns. The data demonstrate that examining plastic surgery revenue can be a useful tool to analyze and possibly predict trends, as it is driven by a market and shows a close correlation to many leading economic indicators. The persisting and increasing interest in plastic surgery suggests hope for a recovering and successful market in the near future.

Flotation separation of waste plastics for recycling-A review.

PubMed

Wang, Chong-qing; Wang, Hui; Fu, Jian-gang; Liu, You-nian

2015-07-01

The sharp increase of plastic wastes results in great social and environmental pressures, and recycling, as an effective way currently available to reduce the negative impacts of plastic wastes, represents one of the most dynamic areas in the plastics industry today. Froth flotation is a promising method to solve the key problem of recycling process, namely separation of plastic mixtures. This review surveys recent literature on plastics flotation, focusing on specific features compared to ores flotation, strategies, methods and principles, flotation equipments, and current challenges. In terms of separation methods, plastics flotation is divided into gamma flotation, adsorption of reagents, surface modification and physical regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modified pavement cement concrete

NASA Astrophysics Data System (ADS)

Botsman, L. N.; Ageeva, M. S.; Botsman, A. N.; Shapovalov, S. M.

2018-03-01

The paper suggests design principles of pavement cement concrete, which covers optimization of compositions and structures at the stage of mixture components selection due to the use of plasticizing agents and air-retaining substances that increase the viability of a concrete mixture. It also demonstrates advisability of using plasticizing agents together with air-retaining substances when developing pavement concrete compositions, which provides for the improvement of physical and mechanical properties of concrete and the reduction of cement binding agent consumption thus preserving strength indicators. The paper shows dependences of the main physical-mechanical parameters of concrete on cement consumption, a type and amount of additives.

Thermodynamic Investigation of the Interaction between Polymer and Gases

NASA Astrophysics Data System (ADS)

Mahmood, Syed Hassan

This thesis investigates the interaction between blowing agents and polymer matrix. Existing theoretical model was further developed to accommodate the polymer and blowing agent under study. The obtained results are not only useful for the optimization of the plastic foam fabrication process but also provides a different approach to usage of blowing agents. A magnetic suspension balance and an in-house visualizing dilatometer were used to obtain the sorption of blowing agents in polymer melts under elevated temperature and pressure. The proposed theoretical approach based on the thermodynamic model of SS-EOS is applied to understand the interaction of blowing agents with the polymer melt and one another (in the case of blend blowing agent). An in-depth study of the interaction of a blend of CO2 and DME with PS was conducted. Experimental volume swelling of the blend/PS mixture was measured and compared to the theoretical volume swelling obtained via ternary based SS-EOS, insuring the models validity. The effect of plasticization due to dissolution of DME on the solubility of CO2 in PS was then investigated by utilizing the aforementioned model. It was noted that the dissolution of DME increased the concentration of CO2 in PS and lowering the saturation pressure needed to dissolved a certain amount of CO2 in PS melt. The phenomenon of retrograde vitrification in PMMA induced due dissolution of CO2 was investigated in light of the thermodynamic properties resulting from the interaction of polymer and blowing agent. Solubility and volume swelling were measured in the pressure and temperature ranges promoting vitrification phenomenon, with relation being established between the thermodynamic properties and the vitrification process. Foaming of PMMA was conducted at various temperature values to investigate the application of this phenomenon.

Predicting the apparent viscosity and yield stress of mixtures of primary, secondary and anaerobically digested sewage sludge: Simulating anaerobic digesters.

PubMed

Markis, Flora; Baudez, Jean-Christophe; Parthasarathy, Rajarathinam; Slatter, Paul; Eshtiaghi, Nicky

2016-09-01

Predicting the flow behaviour, most notably, the apparent viscosity and yield stress of sludge mixtures inside the anaerobic digester is essential because it helps optimize the mixing system in digesters. This paper investigates the rheology of sludge mixtures as a function of digested sludge volume fraction. Sludge mixtures exhibited non-Newtonian, shear thinning, yield stress behaviour. The apparent viscosity and yield stress of sludge mixtures prepared at the same total solids concentration was influenced by the interactions within the digested sludge and increased with the volume fraction of digested sludge - highlighted using shear compliance and shear modulus of sludge mixtures. However, when a thickened primary - secondary sludge mixture was mixed with dilute digested sludge, the apparent viscosity and yield stress decreased with increasing the volume fraction of digested sludge. This was caused by the dilution effect leading to a reduction in the hydrodynamic and non-hydrodynamic interactions when dilute digested sludge was added. Correlations were developed to predict the apparent viscosity and yield stress of the mixtures as a function of the digested sludge volume fraction and total solids concentration of the mixtures. The parameters of correlations can be estimated using pH of sludge. The shear and complex modulus were also modelled and they followed an exponential relationship with increasing digested sludge volume fraction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Waste plastics as supplemental fuel in the blast furnace process: improving combustion efficiencies.

PubMed

Kim, Dongsu; Shin, Sunghye; Sohn, Seungman; Choi, Jinshik; Ban, Bongchan

2002-10-14

The possibility of using waste plastics as a source of secondary fuel in a blast furnace has been of recent interest. The success of this process, however, will be critically dependent upon the optimization of operating systems. For instance, the supply of waste plastics must be reliable as well as economically attractive compared with conventional secondary fuels such as heavy oil, natural gas and pulverized coal. In this work, we put special importance on the improvement of the combustibility of waste plastics as a way to enhance energy efficiency in a blast furnace. As experimental variables to approach this target, the effects of plastic particle size, blast temperature, and the level of oxygen enrichment were investigated using a custom-made blast model designed to simulate a real furnace. Lastly, the combustion efficiency of the mixture of waste plastics and pulverized coal was tested. The observations made from these experiments led us to the conclusion that with the increase of both blast temperature and the level of oxygen enrichment, and with a decrease in particle size, the combustibility of waste polyethylene could be improved at a given distance from the tuyere. Also it was found that the efficiency of coal combustion decreased with the addition of plastics; however, the combustion efficiency of mixture could be comparable at a longer distance from the tuyere.

Suicide by plastic bag suffocation combined with the mixture of citric acid and baking soda in an adolescent.

PubMed

Murakami, Keishu; Kawaguchi, Takashi; Hashizume, Yumiko; Kitamura, Kengo; Okada, Misato; Okumoto, Kohei; Sakamoto, Shoich; Ishida, Yuko; Nosaka, Mizuho; Kimura, Akihiko; Takatsu, Akihiro; Kondo, Toshikazu

2018-05-22

We describe a case of suicidal asphyxiation using a plastic bag combined with carbon dioxide (CO 2 ) gas. A 20-year-old male, whose head was covered with a plastic bag, was found dead in his room. In the plastic bag, there were two glass-made cups containing liquid-like substance. Through crime scene investigation by police staffs, a bottle of citric acid and a box of baking soda were also discovered in his room. The forensic autopsy revealed that there were neither lesions nor injuries in all of the organs. Moreover, any drugs and poisons could not be detected in blood samples. Based on autopsy findings and crime scene investigation, the cause of death was diagnosed as acute asphyxia due to CO 2 intoxication by the mixture of citric acid with baking soda in the plastic bag. To the best of our knowledge, there are no medical literatures describing plastic bag suffocation combined with CO 2 gas generated from citric acid and baking soda, which has been widely distributed as suicidal means through websites. This case report promotes forensic pathologists and medical coroners to emphasize that the Internet has a crucial role on a source of suicidal information or a promoter of suicide all over the world.

High-throughput NIR spectroscopic (NIRS) detection of microplastics in soil.

PubMed

Paul, Andrea; Wander, Lukas; Becker, Roland; Goedecke, Caroline; Braun, Ulrike

2018-05-12

The increasing pollution of terrestrial and aquatic ecosystems with plastic debris leads to the accumulation of microscopic plastic particles of still unknown amount. To monitor the degree of contamination, analytical methods are urgently needed, which help to quantify microplastics (MP). Currently, time-costly purified materials enriched on filters are investigated both by micro-infrared spectroscopy and/or micro-Raman. Although yielding precise results, these techniques are time consuming, and are restricted to the analysis of a small part of the sample in the order of few micrograms. To overcome these problems, we tested a macroscopic dimensioned near-infrared (NIR) process-spectroscopic method in combination with chemometrics. For calibration, artificial MP/ soil mixtures containing defined ratios of polyethylene, polyethylene terephthalate, polypropylene, and polystyrene with diameters < 125 μm were prepared and measured by a process FT-NIR spectrometer equipped with a fiber-optic reflection probe. The resulting spectra were processed by chemometric models including support vector machine regression (SVR), and partial least squares discriminant analysis (PLS-DA). Validation of models by MP mixtures, MP-free soils, and real-world samples, e.g., fermenter residue, suggests a reliable detection and a possible classification of MP at levels above 0.5 to 1.0 mass% depending on the polymer. The benefit of the combined NIRS chemometric approach lies in the rapid assessment whether soil contains MP, without any chemical pretreatment. The method can be used with larger sample volumes and even allows for an online prediction and thus meets the demand of a high-throughput method.

Characterization of Mixtures. Part 2: QSPR Models for Prediction of Excess Molar Volume and Liquid Density Using Neural Networks.

PubMed

Ajmani, Subhash; Rogers, Stephen C; Barley, Mark H; Burgess, Andrew N; Livingstone, David J

2010-09-17

In our earlier work, we have demonstrated that it is possible to characterize binary mixtures using single component descriptors by applying various mixing rules. We also showed that these methods were successful in building predictive QSPR models to study various mixture properties of interest. Here in, we developed a QSPR model of an excess thermodynamic property of binary mixtures i.e. excess molar volume (V(E) ). In the present study, we use a set of mixture descriptors which we earlier designed to specifically account for intermolecular interactions between the components of a mixture and applied successfully to the prediction of infinite-dilution activity coefficients using neural networks (part 1 of this series). We obtain a significant QSPR model for the prediction of excess molar volume (V(E) ) using consensus neural networks and five mixture descriptors. We find that hydrogen bond and thermodynamic descriptors are the most important in determining excess molar volume (V(E) ), which is in line with the theory of intermolecular forces governing excess mixture properties. The results also suggest that the mixture descriptors utilized herein may be sufficient to model a wide variety of properties of binary and possibly even more complex mixtures. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CORRELATION OF THE GLASS TRANSITION TEMPERATURE OF PLASTICIZED PVC USING A LATTICE FLUID MODEL

EPA Science Inventory

A model has been developed to describe the composition dependence of the glass transition temperature (Tg) of polyvinyl chloride (PVC) + plasticizer mixtures. The model is based on Sanchez-Lacombe equation of state and the Gibbs-Di Marzio criterion, which states that th...

CONTINUOUS MICRO-SORTING OF COMPLEX WASTE PLASTICS PARTICLEMIXTURES VIA LIQUID-FLUIDIZED BED CLASSIFICATION (LFBC) FOR WASTE MINIMIZATIONAND RECYCLING

EPA Science Inventory

A fundamental investigation is proposed to provide a technical basis for the development of a novel, liquid-fluidized bed classification (LFBC) technology for the continuous separation of complex waste plastic mixtures for in-process recycling and waste minimization. Although ...

Volume gratings and welding of glass/plastic by femtosecond laser direct writing

NASA Astrophysics Data System (ADS)

Watanabe, Wataru

2018-01-01

Femtosecond laser direct writing is used to fabricate diffractive optical elements in three dimensions and to weld glass and/or plastic. In this paper, we review volume gratings in plastics and welding of glass/plastic by femtosecond laser direct writing. Volume gratings were embedded inside polymethyl methacrylate (PMMA) by femtosecond laser pulses. The diffraction efficiency of the gratings increased after fabrication and reached the maximum. After an initial slow decrease within first several days after the fabrication, the efficiency increased again. This phenomena was called regeneration of the grating. We also demonstrate welding of PMMA by dendrite pattern using femtosecond laser pulses. Laser pulses are focused at the interface of two PMMA substrates with an air gap and melted materials in laser-irradiated region spread within a gap of the substrates and dendrite morphology of melted PMMA was observed outside the laser irradiated area. Finally, we show welding of glass/plastic and metal.

The effects of ingested plastic on growth and survival of albatross chicks

USGS Publications Warehouse

Sievert, Paul R.; Sileo, Louis

1993-01-01

We studied the effects of ingested plastic on the growth and survival of chicks of Laysan Albatrosses Diomedea immutabilis and Black-footed albatrosses D. nigripes on Midway Atoll during the nesting seasons of 1986 and 1987. Weights and proventricular contents of the chicks were determined periodically through the nesting cycle. Large (>22 cm1)volumes of plastic were present in the proventriculi of 27% of the Laysan and 16% of the Black-footed albatross chicks examined by endoscopy. Prior to fledging, albatross chicks regurgitated pellets composed of plastic and other indigestible material from their proventriculi. Laysan Albatross chicks with large volumes of proventricular plastic had asymptotic fledging weights significantly lower (122 g) than did chicks with low amounts of plastic. The effect of depresses fledging weights on postfledging survival was not determined. Plastic had no detectable effect on the growth of Black-footed Albatross chicks. All chicks that died were examined by necropsy. Mechanical lesions from ingested plastic were the cause of death of one of 45 Laysan Albatross chicks examined in 1986, but were not the cause of death of 93 individuals examined in 1987. Dehydration was the most common cause of death. In general, ingested plastic was not a significant direct cause of death in nestlings, but there was some evidence that it may have affected survival in 1986, when the volume of plastic ingested was highest.

Separation of plastics by froth flotation. The role of size, shape and density of the particles.

PubMed

Pita, Fernando; Castilho, Ana

2017-02-01

Over the last few years, new methods for plastic separation in mining have been developed. Froth flotation is one of these techniques, which is based on hydrophobicity differences between particles. Unlike minerals, most of the plastics are naturally hydrophobic, thus requiring the addition of chemicals that promote the selective wettability of one of its components, for a flotation separation. The floatability of six granulated post-consumer plastic - Polystyrene (PS), Polymethyl methacrylate (PMMA), Polyethylene Terephthalate (PET-S, PET-D) and Polyvinyl Chloride (PVC-M, PVC-D) - in the presence of tannic acid (wetting agent), and the performance of the flotation separation of five bi-component plastic mixtures - PS/PMMA, PS/PET-S, PS/PET-D, PS/PVC-M and PS/PVC-D - were evaluated. Moreover, the effect of the contact angle, density, size and shape of the particles was also analysed. Results showed that all plastics were naturally hydrophobic, with PS exhibiting the highest floatability. The contact angle and the flotation recovery of six plastics decreased with increasing tannic acid concentration, occurring depression of plastics at very low concentrations. Floatability differed also with the size and shape of plastic particles. For regular-shaped plastics (PS, PMMA and PVC-D) floatability decreased with the increase of particle size, while for lamellar-shaped particles (PET-D) floatability was slightly greater for coarser particles. Thus, plastic particles with small size, lamellar shape and low density present a greater floatability. The quality of separation varied with the mixture type, depending not only on the plastics hydrophobicity, but also on the size, density and shape of the particles, i.e. the particle weight. Flotation separation of plastics can be enhanced by differences in hydrophobicity. In addition, flotation separation improves if the most hydrophobic plastic, that floats, has a lamellar shape and lower density and if the most hydrophilic plastic, that sinks, has a regular shape and higher density. The results obtained show that froth flotation is a potential method for plastics separation, in particular for plastics with particle size greater than 2.0mm. Copyright © 2016 Elsevier Ltd. All rights reserved.

Resident operative experience in general surgery, plastic surgery, and urology 5 years after implementation of the ACGME duty hour policy.

PubMed

Simien, Christopher; Holt, Kathleen D; Richter, Thomas H; Whalen, Thomas V; Coburn, Michael; Havlik, Robert J; Miller, Rebecca S

2010-08-01

Resident duty hour restrictions were implemented in 2002-2003. This study examines changes in resident surgical experience since these restrictions were put into place. Operative log data for 3 specialties were examined: general surgery, urology, and plastic surgery. The academic year immediately preceding the duty hour restrictions, 2002-2003, was used as a baseline for comparison to subsequent academic years. Operative log data for graduating residents through 2007-2008 were the primary focus of the analysis. Examination of associated variables that may moderate the relationship between fewer duty hours and surgical volume was also included. Plastic surgery showed no changes in operative volume following duty hour restrictions. Operative volume increased in urology programs. General surgery showed a decrease in volume in some operative categories but an increase in others. Specifically the procedures in vascular, plastic, and thoracic areas showed a consistent decrease. There was no increase in the percentage of programs' graduates falling below minimum requirements. Procedures in pancreas, endocrine, and laparoscopic areas demonstrated an increase in volume. Graduates in larger surgical programs performed fewer procedures than graduates in smaller programs; this was not the case for urology or plastic surgery programs. The reduction of duty hours has not resulted in an across the board decrease in operative volume. Factors other than duty hour reforms may be responsible for some of the observed findings.

Application and Testing of Transparent Plastics Used in Airplane Construction

NASA Technical Reports Server (NTRS)

Riechers, K; Olms, J

1938-01-01

This report concerns the efforts being made to remove the source of danger to passengers arising from the fracturing of silicate glass. Some of the alternatives presented include: single-layer safety glass, multi-layer safety glass, transparent plastic resins. Some of the resins considered are celluloid, cellulose acetates, and mixtures of polymers.

Ultrapyrolytic upgrading of plastic wastes and plastics/heavy oil mixtures to valuable light gas products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lovett, S.; Berruti, F.; Behie, L.A.

1997-11-01

Viable operating conditions were identified experimentally for maximizing the production of high-value products such as ethylene, propylene, styrene, and benzene, from the ultrapyrolysis of waste plastics. Using both a batch microreactor and a pilot-plant-sized reactor, the key operating variables considered were pyrolysis temperature, product reaction time, and quench time. In the microreactor experiments, polystyrene (PS), a significant component of waste plastics, was pyrolyzed at temperatures ranging from 800 to 965 C, with total reaction times ranging from 500 to 1,000 ms. At a temperature of 965 C and 500 ms, the yields of styrene plus benzene were greater than 95more » wt %. In the pilot-plant experiments, the recently patented internally circulating fluidized bed (ICFB) reactor (Milne et al., US Patent Number 5,370,789, 1994b) was used to ultrapyrolyze low-density polyethylene (LDPE) in addition to LDPE (5% by weight)/heavy oil mixtures at a residence time of 600 ms. Both experiments produced light olefin yields greater than 55 wt % at temperatures above 830 C.« less

Flotability and flotation separation of polymer materials modulated by wetting agents.

PubMed

Wang, Hui; Wang, Chong-qing; Fu, Jian-gang; Gu, Guo-hua

2014-02-01

The surface free energy, surface tension and contact angles were performed to investigate the properties of wetting agents. Adsorption of wetting agents changes wetting behavior of polymer resins. Flotability of polymer materials modulated by wetting agents was studied, and wetting agents change significantly flotability of polymer materials. The flotability decreases with increasing the concentration of wetting agents, and the wetting ability is lignin sulfonate (LS)>tannic acid (TA)>methylcellulose (MC)>triton X-100 (TX-100) (from strong to weak). There is significant difference in the flotability between polymer resins and plastics due to the presence of additives in the plastics. Flotation separation of two-component and multicomponent plastics was conducted based on the flotability modulated by wetting agents. The two-component mixtures can be efficiently separated using proper wetting agent through simple flotation flowsheet. The multicomponent plastic mixtures can be separated efficiently through multi-stage flotation using TA and LS as wetting agents, and the purity of separated component was above 94%, and the recovery was more than 93%. Copyright © 2013 Elsevier Ltd. All rights reserved.

In Place Soil Treatments for Prevention of Explosives Contamination

DTIC Science & Technology

2010-01-01

gallon plastic drums. Treatment Layer Preparation The PMSO mixture was prepared in a ratio of peat moss and crude soybean oil of 1:1 (w:w). The...PMSO was prepared in batches using a small tow-behind plastic drum gas cement mixer (9 cu. ft capacity). Peat moss bags were weighed, and then emptied...wrap (or other applicable shipping materials) and shipped in plastic coolers by a commercial carrier priority overnight in ice. Holding Times

Upcycling: converting waste plastics into paramagnetic, conducting, solid, pure carbon microspheres.

PubMed

Pol, Vilas Ganpat

2010-06-15

The recent tremendous increase in the volume of waste plastics (WP) will have a harmful environmental impact on the health of living beings. Hundreds of years are required to degrade WP in atmospheric conditions. Hence, in coming years, in addition to traditional recycling services, innovative "upcycling" processes are necessary. This article presents an environmentally benign, solvent-free autogenic process that converts various WP [low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene terephthalate (PET), polystyrene (PS), or their mixtures] into carbon microspheres (CMSs), an industrially significant, value-added product. The thermal dissociation of these individual or mixed WP in a closed reactor under autogenic pressure ( approximately 1000 psi) produced dry, pure powder of CMSs. In this paper, the optimization of process parameters such as the effect of mixing of WP with other materials, and the role of reaction temperature and time are reported. Employing advanced analytical techniques, the atomic structure, composition, and morphology of as-obtained CMSs were analyzed. The room-temperature paramagnetism in CMSs prepared from waste LDPE, HDPE, and PS was further studied by electron paramagnetic resonance (EPR). The conducting and paramagnetic nature of CMSs holds promise for their potential applications in toners, printers, paints, batteries, lubricants, and tires.

Measuring and Modeling Xenon Uptake in Plastic Beta-Cells

NASA Astrophysics Data System (ADS)

Suarez, R.; Hayes, J. C.; Harper, W. W.; Humble, P.; Ripplinger, M. D.; Stephenson, D. E.; Williams, R. M.

2013-12-01

The precision of the stable xenon volume measurement in atmospheric monitoring radio-xenon systems is a critical parameter used to determine the activity concentration of a radio-xenon sample. Typically these types of systems use a plastic scintillating beta-cell as part of a beta-gamma detection scheme to measure the radioactivity present in the gas sample. Challenges arise when performing the stable xenon calculation during or after radioactive counting of the sample due to xenon uptake into the plastic beta-cells. Plastic beta cells can adsorb as much as 5% of the sample during counting. If quantification is performed after counting, the uptake of xenon into the plastic results in an underestimation of the xenon volume measurement. This behavior also causes what is typically known as 'memory effect' in the cell. Experiments were conducted using a small volume low pressure range thermal conductivity sensor to quantify the amount of xenon uptake into the cell over a given period of time. Understanding the xenon uptake in the cell provides a better estimate of the stable volume which improves the overall measurement capability of the system. The results from these experiments along with modeling will be presented.

Learning about natural variation of odor mixtures enhances categorization in early olfactory processing.

PubMed

Locatelli, Fernando F; Fernandez, Patricia C; Smith, Brian H

2016-09-01

Natural odors are typically mixtures of several chemical components. Mixtures vary in composition among odor objects that have the same meaning. Therefore a central 'categorization' problem for an animal as it makes decisions about odors in natural contexts is to correctly identify odor variants that have the same meaning and avoid variants that have a different meaning. We propose that identified mechanisms of associative and non-associative plasticity in early sensory processing in the insect antennal lobe and mammalian olfactory bulb are central to solving this problem. Accordingly, this plasticity should work to improve categorization of odors that have the opposite meanings in relation to important events. Using synthetic mixtures designed to mimic natural odor variation among flowers, we studied how honey bees learn about and generalize among floral odors associated with food. We behaviorally conditioned honey bees on a difficult odor discrimination problem using synthetic mixtures that mimic natural variation among snapdragon flowers. We then used calcium imaging to measure responses of projection neurons of the antennal lobe, which is the first synaptic relay of olfactory sensory information in the brain, to study how ensembles of projection neurons change as a result of behavioral conditioning. We show how these ensembles become 'tuned' through plasticity to improve categorization of odors that have the different meanings. We argue that this tuning allows more efficient use of the immense coding space of the antennal lobe and olfactory bulb to solve the categorization problem. Our data point to the need for a better understanding of the 'statistics' of the odor space. © 2016. Published by The Company of Biologists Ltd.

Smartphone-aided measurements of the speed of sound in different gaseous mixtures

NASA Astrophysics Data System (ADS)

Parolin, Sara Orsola; Pezzi, Giovanni

2013-11-01

Here we describe classroom-based procedures aiming at the estimation of the speed of sound in different gas mixtures with the help of a plastic drain pipe and two iPhones or iPod touches. The procedures were conceived to be performed with simple and readily available tools.

Smartphone-Aided Measurements of the Speed of Sound in Different Gaseous Mixtures

ERIC Educational Resources Information Center

Parolin, Sara Orsola; Pezzi, Giovanni

2013-01-01

Here we describe classroom-based procedures aiming at the estimation of the speed of sound in different gas mixtures with the help of a plastic drain pipe and two iPhones or iPod touches. The procedures were conceived to be performed with simple and readily available tools.

Controlling the rheological behavior of ceramic slurries and consolidated bodies: Interpenetrating networks and ion size effects

NASA Astrophysics Data System (ADS)

Fisher, Matthew Lyle

Colloidal processing has been demonstrated as an effective technique for increasing the reliability of ceramic components by reducing the flaw populations in sintered bodies. The formation of long-range repulsive potentials produces a dispersed slurry which can be filtered to remove heterogeneities and truncate the flaw size distribution. When the pair potentials are changed from repulsive to weakly attractive, a short-range repulsive potential can be developed in the slurry state which prevents mass segregation, allows particles to consolidate to high volume fractions, and produces plastic consolidated bodies. Plastic behavior in saturated ceramic compacts would allow plastic shape forming technologies to be implemented on advanced ceramic powders. Two networks of different interparticle potential have been mixed to control the rheological properties of slurries and develop clay-like plasticity in consolidated bodies. The elastic modulus and yield stress of slurries were found to increase with volume fraction in a power law fashion. Consolidated bodies containing mixtures of alkylated and non-alkylated powder pack to high volume fraction and exhibit similar flow properties to clay. The mixing of aqueous networks of different pair potential can also be effective in tailoring the flow properties. The flow stress of saturated compacts has been adjusted by the addition of a second network of uncoated particles which is stabilized electrostatically. The influence of the addition of silica of various sizes on the viscosity and zeta potentials of alumina suspensions has been investigated. The adsorption of nano-silica to the surface of alumina shifts the iep. The amount of silica at which the maximum shift in zeta potential occurs is consistent with the silica required to produce the minimum viscosity. This level of silica on the surface is consistent with calculations of the amount necessary for dense random parking of silica spheres around alumina. The influence of counterion size on short range repulsive forces at high salt concentrations was investigated with alumina and silica slurries coagulated with the chlorides of Li+, Na+, K+, Cs+ and TMA+ (tetramethylammonium+). The results clearly show that the range of the repulsive forces correlated with the size of the unhydrated ion, namely stronger particle networks are achieved with smaller counterions. The findings are contradictory to the widely accepted hydration force model. Silica and alumina slurries were also studied at and below the iep where the indifferent electrolyte cations would not be expected to adsorb. It appears that a lyotropic sequence for excluded ions exists and is correlated to the hydration of ions and surfaces.

A mixture of five phthalate diesters cummulatively inhibit fetal testicular testoserone production in a manner consisent with their predicted reporduction toxicity in the Sprague Dawley rat.

EPA Science Inventory

Phthalate diesters are commonly-used plasticizers in intravenous bags, plastic food wrap and children’s toys, and the metabolites of multiple phthalates are detected in humans. In utero exposure to certain phthalates during sexual differentiation causes male reproductive tract m...

Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: influence of lapse time of reaction.

PubMed

Lee, Kyong-Hwan; Shin, Dae-Hyun

2007-01-01

Pyrolysis of a waste plastic mixture (high-density polyethylene: low-density polyethylene: polypropylene: polystyrene = 3:2:3:1) into a liquid product was carried out in a stirred semi-batch reactor at low (350 degrees C) and high (400 degrees C) temperatures. The effect of lapse time of reaction in the reactor and also degradation temperature on the characteristics of the liquid product from pyrolysis of the mixture was investigated. Liquid products were described by cumulative amount distribution, paraffin, olefin, naphthene and aromatic (PONA) distribution and molecular weight distribution. Their characteristic was quite differed with a lapse time of reaction and also at a low and high degradation temperatures, because of the different physicochemical properties of the plastic types in the mixture. With increase of lapse time of reaction, the order for the main products in PONA components obtained at 350 degrees C was firstly aromatic products and then olefin products, while at 400 degrees C the order was firstly aromatic products, then olefin products and finally paraffin products. The experiments also showed from the molecular weight distribution of liquid PONA components that the paraffin and olefin products had a wide distribution by mainly random scission of polymer, but in the case of olefin products were produced by an end-chain scission mechanism as well as random scission mechanism, as evidenced by much more light olefin products. This phenomenon was evident at a higher degradation temperature. Also, both the light olefin and naphthene products with a molecular weight of around 120, as a main product, showed a similar trend as a function of lapse time, which had a maximum fraction at 343 min (at 350 degrees C) and 83 min (at 400 degrees C). Among PONA components, the highest concentrations of aromatic products were obtained with a molecular weight of around 100 at the fastest lapse time of reaction, regardless of degradation temperature. It was concluded that the characteristics of liquid product on the pyrolysis of plastic mixtures were strongly influenced by lapse time of reaction and degradation temperature.

Some engineering aspects of homoionized mixed clay minerals.

PubMed

Oren, Ali Hakan; Kaya, Abidin

2003-05-01

Many studies have been conducted to investigate the physicochemical behavior of pure clay minerals and predict their engineering performance in the field. In this study, the physicochemical properties of an artificial mixture of different clay minerals namely, 40-50% montmorillonite, 20-30% illite and 10-15% kaolin were investigated. The mixture was homoionized with sodium, Na+; calcium, Ca2+; and aluminum, Al3+. The engineering properties studied were consistency limits, sediment volume, compressibility behavior, and hydraulic conductivity. The results revealed that the liquid, plastic and shrinkage limits of soil increased with increasing cation valence. The hydraulic conductivity of the soil also increased with an increase in the valence of the cation at any given void ratio. Aluminum and sodium treated clays had the highest and the lowest modified compression index values, respectively. Furthermore, trivalent cation saturated clayey soil consolidates three times faster than that of monovalent and two times faster than that of divalent. These properties of the soils determined were, in general, similar to those of kaolinite rather than those of montmorillonite. The comparison of the results obtained with the published data in the literature revealed that the physicochemical behavior of the tested clay soil was, in general, similar to that of kaolinite.

Thermal activation parameters of plastic flow reveal deformation mechanisms in the CrMnFeCoNi high-entropy alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laplanche, Guillaume; Bonneville, J.; Varvenne, C.

To reveal the operating mechanisms of plastic deformation in an FCC high-entropy alloy, the activation volumes in CrMnFeCoNi have been measured as a function of plastic strain and temperature between 77 K and 423 K using repeated load relaxation experiments. At the yield stress, σ y, the activation volume varies from ~60 b3 at 77 K to ~360 b 3 at 293 K and scales inversely with yield stress. With increasing plastic strain, the activation volume decreases and the trends follow the Cottrell-Stokes law, according to which the inverse activation volume should increase linearly with σ - σ y (Haasenmore » plot). This is consistent with the notion that hardening due to an increase in the density of forest dislocations is naturally associated with a decrease in the activation volume because the spacing between dislocations decreases. The values and trends in activation volume agree with theoretical predictions that treat the HEA as a high-concentration solid-solution-strengthened alloy. Lastly, these results demonstrate that this HEA deforms by the mechanisms typical of solute strengthening in FCC alloys, and thus indicate that the high compositional/structural complexity does not introduce any new intrinsic deformation mechanisms.« less

Thermal activation parameters of plastic flow reveal deformation mechanisms in the CrMnFeCoNi high-entropy alloy

DOE PAGES

Laplanche, Guillaume; Bonneville, J.; Varvenne, C.; ...

2017-10-06

To reveal the operating mechanisms of plastic deformation in an FCC high-entropy alloy, the activation volumes in CrMnFeCoNi have been measured as a function of plastic strain and temperature between 77 K and 423 K using repeated load relaxation experiments. At the yield stress, σ y, the activation volume varies from ~60 b3 at 77 K to ~360 b 3 at 293 K and scales inversely with yield stress. With increasing plastic strain, the activation volume decreases and the trends follow the Cottrell-Stokes law, according to which the inverse activation volume should increase linearly with σ - σ y (Haasenmore » plot). This is consistent with the notion that hardening due to an increase in the density of forest dislocations is naturally associated with a decrease in the activation volume because the spacing between dislocations decreases. The values and trends in activation volume agree with theoretical predictions that treat the HEA as a high-concentration solid-solution-strengthened alloy. Lastly, these results demonstrate that this HEA deforms by the mechanisms typical of solute strengthening in FCC alloys, and thus indicate that the high compositional/structural complexity does not introduce any new intrinsic deformation mechanisms.« less

Stability of an extemporaneously prepared alcohol-free phenobarbital suspension.

PubMed

Cober, Mary Petrea; Johnson, Cary E

2007-03-15

The physical and chemical short-term stability of alcohol-free, oral suspensions of phenobarbital 10 mg/mL prepared from commercially available tablets in both a sugar and a sugar-free vehicle was assessed at room temperature. Phenobarbital oral suspension 10 mg/mL was prepared by crushing 10 60-mg tablets of phenobarbital with a mortar and pestle. A small amount of Ora-Plus was added to the phenobarbital powder to sufficiently wet the particles. A 1:1 mixture of Ora-Plus and either Ora-Sweet or Ora-Sweet SF was combined with the phenobarbital powder to produce a final volume of 60 mL. Three identical samples of each of the two different formulations were prepared and stored at room temperature in 2-oz amber plastic bottles. Immediately after preparation and at 15, 30, 60, and 115 days, the samples were assayed in duplicate by stability-indicating high-performance liquid chromatography. The samples were tasted and inspected for color and odor changes. The percent of the initial concentration remaining at each study time for each phenobarbital suspension was determined. Stability was defined as the retention of at least 90% of the initial concentration. There were no detectable changes in color, odor, and taste and no visible microbial growth in any sample. At least 98% of the initial phenobarbital concentration remained throughout the 115-day study period in both preparations. An extemporaneously prepared alcohol-free suspension of phenobarbital 10 mg/mL in a 1:1 mixture of Ora-Plus and Ora-Sweet or Ora-Sweet SF was stable for at least 115 days when stored in 2-oz amber plastic bottles at room temperature.

Removal of phenol from aqueous solution using polymer inclusion membrane based on mixture of CTA and CA

NASA Astrophysics Data System (ADS)

Benosmane, Nadjib; Boutemeur, Baya; Hamdi, Safouane M.; Hamdi, Maamar

2018-03-01

Nowadays, there are increasingly stringent regulations requiring more and more treatment of industrial effluents to generate product waters which could be easily reused or disposed of to the environment without any harmful effects. In the present work, the removal of phenol from aqueous solution across polymer inclusion membrane (PIM), based on mixture of cellulose triacetate and cellulose acetate as support (75/25%), calix[4]resorcinarene derivative as a carrier and 2-nitrophenyl octyl ether (2-NPOE) as plasticizer was investigated. The experimental part of this investigation involved the influence of carrier nature, plasticizer concentration, pH phases, and phenol initial concentration on the removal efficiency of phenol from synthetic wastewater. A PIM containing 0.1 g (of mixture polymer), (0.15 g/g mixture of polymer) of carrier and (0.03 ml/g mixture of polymer) of 2-NPOE provided the highest percentage of phenol removal efficiency over a 6-day transport; the removal was found to be about 95%, indeed the removal was found to be highly dependent of pH phases. The feed solution in these transport experiments was at pH 2, while the stripping solution contained 0.20 M NaOH. This study claims that the PIM with a mixture of cellulose derivatives can be used effectively to remove phenols from wastewaters.

Load partitioning in Ai{sub 2}0{sub 3-}Al composites with three- dimensional periodic architecture.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, M. L.; Rao, R.; Almer, J. D.

2009-05-01

Interpenetrating composites are created by infiltration of liquid aluminum into three-dimensional (3-D) periodic Al{sub 2}O{sub 3} preforms with simple tetragonal symmetry produced by direct-write assembly. Volume-averaged lattice strains in the Al{sub 2}O{sub 3} phase of the composite are measured by synchrotron X-ray diffraction for various uniaxial compression stresses up to -350MPa. Load transfer, found by diffraction to occur from the metal phase to the ceramic phase, is in general agreement with simple rule-of-mixture models and in better agreement with more complex, 3-D finite-element models that account for metal plasticity and details of the geometry of both phases. Spatially resolved diffractionmore » measurements show variations in load transfer at two different positions within the composite.« less

Compaction-Based Deformable Terrain Model as an Interface for Real-Time Vehicle Dynamics Simulations

DTIC Science & Technology

2013-04-16

to vehicular loads, and the resulting visco-elastic-plastic stress/strain on the affected soil volume. Pedo transfer functions allow for the...resulting visco-elastic-plastic stress/strain on the affected soil volume. Pedo transfer functions allow for the calculation of the soil mechanics model

Linking the structures, free volumes, and properties of ionic liquid mixtures† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7sc01407d

PubMed Central

Brooks, Nicholas J.; Castiglione, Franca; Doherty, Cara M.; Dolan, Andrew; Hill, Anita J.; Hunt, Patricia A.; Matthews, Richard P.; Mauri, Michele; Mele, Andrea; Simonutti, Roberto; Villar-Garcia, Ignacio J.; Weber, Cameron C.

2017-01-01

The formation of ionic liquid (IL) mixtures has been proposed as an approach to rationally fine-tune the physicochemical properties of ILs for a variety of applications. However, the effects of forming such mixtures on the resultant properties of the liquids are only beginning to be understood. Towards a more complete understanding of both the thermodynamics of mixing ILs and the effect of mixing these liquids on their structures and physicochemical properties, the spatial arrangement and free volume of IL mixtures containing the common [C4C1im]+ cation and different anions have been systematically explored using small angle X-ray scattering (SAXS), positron annihilation lifetime spectroscopy (PALS) and 129Xe NMR techniques. Anion size has the greatest effect on the spatial arrangement of the ILs and their mixtures in terms of the size of the non-polar domains and inter-ion distances. It was found that differences in coulombic attraction between oppositely charged ions arising from the distribution of charge density amongst the atoms of the anion also significantly influences these inter-ion distances. PALS and 129Xe NMR results pertaining to the free volume of these mixtures were found to strongly correlate with each other despite the vastly different timescales of these techniques. Furthermore, the excess free volumes calculated from each of these measurements were in excellent agreement with the excess volumes of mixing measured for the IL mixtures investigated. The correspondence of these techniques indicates that the static and dynamic free volume of these liquid mixtures are strongly linked. Consequently, fluxional processes such as hydrogen bonding do not significantly contribute to the free volumes of these liquids compared to the spatial arrangement of ions arising from their size, shape and coulombic attraction. Given the relationship between free volume and transport properties such as viscosity and conductivity, these results provide a link between the structures of IL mixtures, the thermodynamics of mixing and their physicochemical properties. PMID:29619199

Volume reduction of hot cell plastic wastes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dykes, F W; Henscheid, J P; Lewis, L C

1989-09-19

The disposal of radioactively-contaminated solid wastes has become a national crisis. In such circumstances, it is imperative that this waste be reduced to minimum volume and be packaged to prevent pollution of the environment. The majority of the solid waste generated at the hot cell under consideration is plastic lab ware. Cutting this waste into small pieces with a hot wire technique reduced the volume 66%. Melting the waste, although more time consuming, reduced the volume 90%. The hot wire technique can also be used to cut up damaged master slave manipulator boots, greatly reducing their disposal volume.

Consumer Exposure to Bisphenol A from Plastic Bottles

ERIC Educational Resources Information Center

Bidabadi, Fatemeh

2013-01-01

Bisphenol A (BPA) is a plastic monomer and plasticizer and is a chemical that has one of the highest volume production worldwide, with more than six billion pounds each year. Its primary use is the production of polycarbonate plastics, epoxy resins used to line metal cans in a host of plastic consumer products such as toys, water pipes, drinking…

Structure formation control of foam concrete

NASA Astrophysics Data System (ADS)

Steshenko, Aleksei; Kudyakov, Aleksander; Konusheva, Viktoriya; Syrkin, Oleg

2017-01-01

The process of predetermined foam concrete structure formation is considered to be a crucial issue from the point of process control and it is currently understudied thus defining the need for additional research. One of the effective ways of structure formation control in naturally hardening foam concrete is reinforcement with dispersed fibers or introduction of plasticizers. The paper aims at studying the patterns of influence of microreinforcing and plasticizing additives on the structure and performance properties of foam concrete. Preparation of foam concrete mix has been conducted using one-step technology. The structure of modified foam concrete has been studied by means of electron microscopy. The cellular structure of foam concrete samples with the additives is homogeneous; the pores are uniformly distributed over the total volume. It has been revealed that introduction of the Neolas 5.2 plasticizer and microreinforcing fibers in the foam concrete mixture in the amount of 0.4 - 0.1 % by weight of cement leads to reduction of the average pore diameter in the range of 45.3 to 30.2 microns and the standard deviation of the pore average diameter from 23.6 to 9.2 in comparison with the sample without additive. Introduction of modifying additives has stimulated formation of a large number of closed pores. Thus porosity of conditionally closed pores has increased from 16.06 % to 34.48 %, which has lead to increase of frost resistance brand of foam concrete from F15 to F50 and to reduction of its water absorption by weight by 20 %.

Stoichiometric Experiments with Alkane Combustion: A Classroom Demonstration

ERIC Educational Resources Information Center

Zhilin, Denis M.

2012-01-01

A simple, effective demonstration of the concept of limiting and excess reagent is presented. Mixtures of either air/methane (from a gas line) or air/butane (from a disposable cigarette lighter) contained in a plastic 2 L soda bottles are ignited. The mixtures combust readily when air/fuel ratios are stoichiometric, but not at a 2-fold excess of…

Plasticity and Ductility in Graphene Oxide Through a Mechanochemically Induced Damage Tolerance Mechanism

DTIC Science & Technology

2015-08-20

potassium permanganate , absolute ethanol, con- centrated hydrochloric acid and n-butylamine (99.5%) were purchased from Sigma-Aldrich Co. LLC (Milwaukee, WI...40ml) was added to a mixture of graphite (3 g) and potassium permanganate (18 g). The reaction mixture was heated to 50 C and stirred for 12 h. The

The Kirkwood-Buff theory of solutions and the local composition of liquid mixtures.

PubMed

Shulgin, Ivan L; Ruckenstein, Eli

2006-06-29

The present paper is devoted to the local composition of liquid mixtures calculated in the framework of the Kirkwood-Buff theory of solutions. A new method is suggested to calculate the excess (or deficit) number of various molecules around a selected (central) molecule in binary and multicomponent liquid mixtures in terms of measurable macroscopic thermodynamic quantities, such as the derivatives of the chemical potentials with respect to concentrations, the isothermal compressibility, and the partial molar volumes. This method accounts for an inaccessible volume due to the presence of a central molecule and is applied to binary and ternary mixtures. For the ideal binary mixture it is shown that because of the difference in the volumes of the pure components there is an excess (or deficit) number of different molecules around a central molecule. The excess (or deficit) becomes zero when the components of the ideal binary mixture have the same volume. The new method is also applied to methanol + water and 2-propanol + water mixtures. In the case of the 2-propanol + water mixture, the new method, in contrast to the other ones, indicates that clusters dominated by 2-propanol disappear at high alcohol mole fractions, in agreement with experimental observations. Finally, it is shown that the application of the new procedure to the ternary mixture water/protein/cosolvent at infinite dilution of the protein led to almost the same results as the methods involving a reference state.

Does size and buoyancy affect the long-distance transport of floating debris?

NASA Astrophysics Data System (ADS)

Ryan, Peter G.

2015-08-01

Floating persistent debris, primarily made from plastic, disperses long distances from source areas and accumulates in oceanic gyres. However, biofouling can increase the density of debris items to the point where they sink. Buoyancy is related to item volume, whereas fouling is related to surface area, so small items (which have high surface area to volume ratios) should start to sink sooner than large items. Empirical observations off South Africa support this prediction: moving offshore from coastal source areas there is an increase in the size of floating debris, an increase in the proportion of highly buoyant items (e.g. sealed bottles, floats and foamed plastics), and a decrease in the proportion of thin items such as plastic bags and flexible packaging which have high surface area to volume ratios. Size-specific sedimentation rates may be one reason for the apparent paucity of small plastic items floating in the world’s oceans.

Modeling the interaction of binary mixtures of estradiol and bisphenol A or its analogues in an in vitro estrogen mediated transcriptional activation assay (T47D-KBluc).

EPA Science Inventory

Bisphenol A (BPA) is a ubiquitous monomer used to manufacture polycarbonate plastics. BPA is used in composites and sealants in dentistry, for epoxy resins used as protective liners in metallic cans, and as additives in various plastics. Approximately 1.7 billion pounds of BPA ...

Compositional and moisture content effects on the biodegradability of zein/ethylcellulose films.

PubMed

Romero-Bastida, Claudia A; Flores-Huicochea, Eduardo; Martin-Polo, Martha O; Velazquez, Gonzalo; Torres, J Antonio

2004-04-21

The effect of moisture content and film composition on biodegradability is the focus of this study. Flexible films were first characterized for the effect on water sorption isotherms of relative humidity, temperature, zein content, and the addition of the plasticizers stearic acid, poly(ethylene glycol), or etoxylated ricine oil. Zein/ethylcellulose (EC) mixture films had a behavior between that for pure zein and EC films, which had the lowest water sorption. For films with plasticizer, the lowest water sorption at 25 degrees C was observed for those with stearic acid. Biodegradability of zein/EC films, evaluated using bacterial cultures selected for their zein proteolytic activity and isolated from a local solid waste landfill and a lagoon, showed no plasticizer effect even though its effect on moisture content was significant. Large differences were observed at different film zein concentration with the highest biodegradability for 100% zein. However, biodegradability did not mimic the water sorption behavior of zein/EC mixture films.

Triboelectrostatic separation of polypropylene, polyurethane, and polyvinylchloride used in passenger vehicles.

PubMed

Li, Tuyu; Yu, Dali; Zhang, Hongshen

2018-03-01

Recycling and reuse of automotive plastics have elicited global attention due to the increasing number of end-of-life vehicles. Through the single-factor experiment, a high-voltage triboelectrostatic sorting device was developed to separate polypropylene (PP), polyurethane (PU), and polyvinylchloride (PVC) in a plastic mixture commonly used in exterior and interior parts of passenger vehicles. Products of PP, PU, and PVC were obtained after two-stage separation; their purity exceeded 95%, and their productivities were 74%, 94%, and 41%, respectively. The appropriate experimental parameters for high voltage level and rotational speed of the friction drum and cylinder electrode for the first stage of separation were 35 kV, 30 rpm, and 35 rpm, respectively, and the parameters for the second stage of separation were 35 kV, 30 rpm, and 25 rpm, respectively. Results showed that hybrid materials should be selected based on the triboelectric series to separate three-component plastic mixtures feasibly. Copyright © 2017 Elsevier Ltd. All rights reserved.

A dislocation-based, strain–gradient–plasticity strengthening model for deformation processed metal–metal composites

DOE PAGES

Tian, Liang; Russell, Alan; Anderson, Iver

2014-01-03

Deformation processed metal–metal composites (DMMCs) are high-strength, high-electrical conductivity composites developed by severe plastic deformation of two ductile metal phases. The extraordinarily high strength of DMMCs is underestimated using the rule of mixture (or volumetric weighted average) of conventionally work-hardened metals. A dislocation-density-based, strain–gradient–plasticity model is proposed to relate the strain-gradient effect with the geometrically necessary dislocations emanating from the interface to better predict the strength of DMMCs. The model prediction was compared with our experimental findings of Cu–Nb, Cu–Ta, and Al–Ti DMMC systems to verify the applicability of the new model. The results show that this model predicts themore » strength of DMMCs better than the rule-of-mixture model. The strain-gradient effect, responsible for the exceptionally high strength of heavily cold worked DMMCs, is dominant at large deformation strain since its characteristic microstructure length is comparable with the intrinsic material length.« less

Plastic strain is a mixture of avalanches and quasireversible deformations: Study of various sizes

NASA Astrophysics Data System (ADS)

Szabó, Péter; Ispánovity, Péter Dusán; Groma, István

2015-02-01

The size dependence of plastic flow is studied by discrete dislocation dynamical simulations of systems with various amounts of interacting dislocations while the stress is slowly increased. The regions between avalanches in the individual stress curves as functions of the plastic strain were found to be nearly linear and reversible where the plastic deformation obeys an effective equation of motion with a nearly linear force. For small plastic deformation, the mean values of the stress-strain curves obey a power law over two decades. Here and for somewhat larger plastic deformations, the mean stress-strain curves converge for larger sizes, while their variances shrink, both indicating the existence of a thermodynamical limit. The converging averages decrease with increasing size, in accordance with size effects from experiments. For large plastic deformations, where steady flow sets in, the thermodynamical limit was not realized in this model system.

Pollutants in Plastics within the North Pacific Subtropical Gyre.

PubMed

Chen, Qiqing; Reisser, Julia; Cunsolo, Serena; Kwadijk, Christiaan; Kotterman, Michiel; Proietti, Maira; Slat, Boyan; Ferrari, Francesco F; Schwarz, Anna; Levivier, Aurore; Yin, Daqiang; Hollert, Henner; Koelmans, Albert A

2018-01-16

Here we report concentrations of pollutants in floating plastics from the North Pacific accumulation zone (NPAC). We compared chemical concentrations in plastics of different types and sizes, assessed ocean plastic potential risks using sediment quality criteria, and discussed the implications of our findings for bioaccumulation. Our results suggest that at least a fraction of the NPAC plastics is not in equilibrium with the surrounding seawater. For instance, "hard plastic" samples had significantly higher PBDE concentrations than "nets and ropes" samples, and 29% of them had PBDE composition similar to a widely used flame-retardant mixture. Our findings indicate that NPAC plastics may pose a chemical risk to organisms as 84% of the samples had at least one chemical exceeding sediment threshold effect levels. Furthermore, our surface trawls collected more plastic than biomass (180 times on average), indicating that some NPAC organisms feeding upon floating particles may have plastic as a major component of their diets. If gradients for pollutant transfer from NPAC plastic to predators exist (as indicated by our fugacity ratio calculations), plastics may play a role in transferring chemicals to certain marine organisms.

The effects of temperature on nitrous oxide and oxygen mixture homogeneity and stability.

PubMed

Litwin, Patrick D

2010-10-15

For many long standing practices, the rationale for them is often lost as time passes. This is the situation with respect to the storage and handling of equimolar 50% nitrous oxide and 50% oxygen volume/volume (v/v) mixtures. A review was undertaken of existing literature to examine the developmental history of nitrous oxide and oxygen mixtures for anesthesia and analgesia and to ascertain if sufficient bibliographic data was available to support the position that the contents of a cylinder of a 50%/50% volume/volume (v/v) mixture of nitrous oxide and oxygen is in a homogenous single gas phase in a filled cylinder under normal conditions of handling and storage and if justification could be found for the standard instructions given for handling before use. After ranking and removing duplicates, a total of fifteen articles were identified by the various search strategies and formed the basis of this literature review. Several studies were identified that confirmed that 50%/50% v/v mixture of nitrous oxide and oxygen is in a homogenous single gas phase in a filled cylinder under normal conditions of handling and storage. The effect of temperature on the change of phase of the nitrous oxide in this mixture was further examined by several authors. These studies demonstrated that although it is possible to cause condensation and phase separation by cooling the cylinder, by allowing the cylinder to rewarm to room temperature for at least 48 hours, preferably in a horizontal orientation, and inverting it three times before use, the cylinder consistently delivered the proper proportions of the component gases as a homogenous mixture. The contents of a cylinder of a 50%/50% volume/volume (v/v) mixture of nitrous oxide and oxygen is in a homogenous single gas phase in a filled cylinder under normal conditions of handling and storage. The standard instructions given for handling before are justified based on previously conducted studies.

Refractive index of liquid mixtures: theory and experiment.

PubMed

Reis, João Carlos R; Lampreia, Isabel M S; Santos, Angela F S; Moita, Maria Luísa C J; Douhéret, Gérard

2010-12-03

An innovative approach is presented to interpret the refractive index of binary liquid mixtures. The concept of refractive index "before mixing" is introduced and shown to be given by the volume-fraction mixing rule of the pure-component refractive indices (Arago-Biot formula). The refractive index of thermodynamically ideal liquid mixtures is demonstrated to be given by the volume-fraction mixing rule of the pure-component squared refractive indices (Newton formula). This theoretical formulation entails a positive change of refractive index upon ideal mixing, which is interpreted in terms of dissimilar London dispersion forces centred in the dissimilar molecules making up the mixture. For real liquid mixtures, the refractive index of mixing and the excess refractive index are introduced in a thermodynamic manner. Examples of mixtures are cited for which excess refractive indices and excess molar volumes show all of the four possible sign combinations, a fact that jeopardises the finding of a general equation linking these two excess properties. Refractive indices of 69 mixtures of water with the amphiphile (R,S)-1-propoxypropan-2-ol are reported at five temperatures in the range 283-303 K. The ideal and real refractive properties of this binary system are discussed. Pear-shaped plots of excess refractive indices against excess molar volumes show that extreme positive values of excess refractive index occur at a substantially lower mole fraction of the amphiphile than extreme negative values of excess molar volume. Analysis of these plots provides insights into the mixing schemes that occur in different composition segments. A nearly linear variation is found when Balankina's ratios between excess and ideal values of refractive indices are plotted against ratios between excess and ideal values of molar volumes. It is concluded that, when coupled with volumetric properties, the new thermodynamic functions defined for the analysis of refractive indices of liquid mixtures give important complementary information on the mixing process over the whole composition range.

Araldite as an Embedding Medium for Electron Microscopy

PubMed Central

Glauert, Audrey M.; Glauert, R. H.

1958-01-01

Epoxy resins are suitable media for embedding for electron microscopy, as they set uniformly with virtually no shrinkage. A mixture of araldite epoxy resins has been developed which is soluble in ethanol, and which yields a block of the required hardness for thin sectioning. The critical modifications to the conventional mixtures are the choice of a plasticized resin in conjunction with an aliphatic anhydride as the hardener. The hardness of the final block can be varied by incorporating additional plasticizer, and the rate of setting can be controlled by the use of an amine accelerator. The properties of the araldite mixture can be varied quite widely by adjusting the proportions of the various constituents. The procedure for embedding biological specimens is similar to that employed with methacrylates, although longer soaking times are recommended to ensure the complete penetration of the more viscous epoxy resin. An improvement in the preservation of the fine structure of a variety of specimens has already been reported, and a typical electron microgram illustrates the present paper. PMID:13525433

Plastic waste to liquid oil through catalytic pyrolysis using natural and synthetic zeolite catalysts.

PubMed

Miandad, R; Barakat, M A; Rehan, M; Aburiazaiza, A S; Ismail, I M I; Nizami, A S

2017-11-01

This study aims to examine the catalytic pyrolysis of various plastic wastes in the presence of natural and synthetic zeolite catalysts. A small pilot scale reactor was commissioned to carry out the catalytic pyrolysis of polystyrene (PS), polypropylene (PP), polyethylene (PE) and their mixtures in different ratios at 450°C and 75min. PS plastic waste resulted in the highest liquid oil yield of 54% using natural zeolite and 50% using synthetic zeolite catalysts. Mixing of PS with other plastic wastes lowered the liquid oil yield whereas all mixtures of PP and PE resulted in higher liquid oil yield than the individual plastic feedstocks using both catalysts. The GC-MS analysis revealed that the pyrolysis liquid oils from all samples mainly consisted of aromatic hydrocarbons with a few aliphatic hydrocarbon compounds. The types and amounts of different compounds present in liquid oils vary with some common compounds such as styrene, ethylbenzene, benzene, azulene, naphthalene, and toluene. The FT-IR data also confirmed that liquid oil contained mostly aromatic compounds with some alkanes, alkenes and small amounts of phenol group. The produced liquid oils have high heating values (HHV) of 40.2-45MJ/kg, which are similar to conventional diesel. The liquid oil has potential to be used as an alternative source of energy or fuel production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mixture quantification using PLS in plastic scintillation measurements.

PubMed

Bagán, H; Tarancón, A; Rauret, G; García, J F

2011-06-01

This article reports the capability of plastic scintillation (PS) combined with multivariate calibration (Partial least squares; PLS) to detect and quantify alpha and beta emitters in mixtures. While several attempts have been made with this purpose in mind using liquid scintillation (LS), no attempt was done using PS that has the great advantage of not producing mixed waste after the measurements are performed. Following this objective, ternary mixtures of alpha and beta emitters ((241)Am, (137)Cs and (90)Sr/(90)Y) have been quantified. Procedure optimisation has evaluated the use of the net spectra or the sample spectra, the inclusion of different spectra obtained at different values of the Pulse Shape Analysis parameter and the application of the PLS1 or PLS2 algorithms. The conclusions show that the use of PS+PLS2 applied to the sample spectra, without the use of any pulse shape discrimination, allows quantification of the activities with relative errors less than 10% in most of the cases. This procedure not only allows quantification of mixtures but also reduces measurement time (no blanks are required) and the application of this procedure does not require detectors that include the pulse shape analysis parameter. Copyright © 2011 Elsevier Ltd. All rights reserved.

Change of hydrogen bonding structure in ionic liquid mixtures by anion type

NASA Astrophysics Data System (ADS)

Cha, Seoncheol; Kim, Doseok

2018-05-01

Ionic liquid mixtures have gained attention as a way of tuning material properties continuously with composition changes. For some mixture systems, physicochemical properties such as excess molar volume have been found to be significantly different from the value expected by linear interpolation, but the origin of this deviation is not well understood yet. The microstructure of the mixture, which can range from an ideal mixture of two initial consisting ionic liquids to a different structure from those of pure materials, has been suggested as the origin of the observed deviation. The structures of several different ionic liquid mixtures are studied by IR spectroscopy to confirm this suggestion, as a particular IR absorption band (νC(2)-D) for the moiety participating in the hydrogen bonding changes sensitively with the change of the anion in the ionic liquid. The absorbance of νC(2)-D changes proportionally with the composition, and a relatively small excess molar volume is observed for the mixtures containing an electronegative halide anion. By contrast, the absorbance changes nonlinearly, and the excess molar volumes are larger for the mixtures of which one of the anions has multiple interaction sites.

Gravel-Sand-Clay Mixture Model for Predictions of Permeability and Velocity of Unconsolidated Sediments

NASA Astrophysics Data System (ADS)

Konishi, C.

2014-12-01

Gravel-sand-clay mixture model is proposed particularly for unconsolidated sediments to predict permeability and velocity from volume fractions of the three components (i.e. gravel, sand, and clay). A well-known sand-clay mixture model or bimodal mixture model treats clay contents as volume fraction of the small particle and the rest of the volume is considered as that of the large particle. This simple approach has been commonly accepted and has validated by many studies before. However, a collection of laboratory measurements of permeability and grain size distribution for unconsolidated samples show an impact of presence of another large particle; i.e. only a few percent of gravel particles increases the permeability of the sample significantly. This observation cannot be explained by the bimodal mixture model and it suggests the necessity of considering the gravel-sand-clay mixture model. In the proposed model, I consider the three volume fractions of each component instead of using only the clay contents. Sand becomes either larger or smaller particles in the three component mixture model, whereas it is always the large particle in the bimodal mixture model. The total porosity of the two cases, one is the case that the sand is smaller particle and the other is the case that the sand is larger particle, can be modeled independently from sand volume fraction by the same fashion in the bimodal model. However, the two cases can co-exist in one sample; thus, the total porosity of the mixed sample is calculated by weighted average of the two cases by the volume fractions of gravel and clay. The effective porosity is distinguished from the total porosity assuming that the porosity associated with clay is zero effective porosity. In addition, effective grain size can be computed from the volume fractions and representative grain sizes for each component. Using the effective porosity and the effective grain size, the permeability is predicted by Kozeny-Carman equation. Furthermore, elastic properties are obtainable by general Hashin-Shtrikman-Walpole bounds. The predicted results by this new mixture model are qualitatively consistent with laboratory measurements and well log obtained for unconsolidated sediments. Acknowledgement: A part of this study was accomplished with a subsidy of River Environment Fund of Japan.

Modeling the interaction of binary mixtures of estradiol and bisphenol A or its analogues in an in vitro estrogen mediated transcriptional activation assay (T47D-KBIuc).

EPA Science Inventory

Bisphenol A (BPA) is a ubiquitous monomer used to manufacture polycarbonate plastics. BPA is used in composites and sealants in dentistry, for epoxy resins used as protective liners in metallic cans, and as additives in various plastics. Approximately 1.7 billion pounds of BPA ar...

Pyrolytic conversion of plastic and rubber waste to hydrocarbons with basic salt catalysts

DOEpatents

Wingfield, Jr., Robert C.; Braslaw, Jacob; Gealer, Roy L.

1985-01-01

The invention relates to a process for improving the pyrolytic conversion of waste selected from rubber and plastic to low molecular weight olefinic materials by employing basis salt catalysts in the waste mixture. The salts comprise alkali or alkaline earth compounds, particularly sodium carbonate, in an amount of greater than about 1 weight percent based on the waste feed.

Original predictive approach to the compressibility of pharmaceutical powder mixtures based on the Kawakita equation.

PubMed

Mazel, Vincent; Busignies, Virginie; Duca, Stéphane; Leclerc, Bernard; Tchoreloff, Pierre

2011-05-30

In the pharmaceutical industry, tablets are obtained by the compaction of two or more components which have different physical properties and compaction behaviours. Therefore, it could be interesting to predict the physical properties of the mixture using the single-component results. In this paper, we have focused on the prediction of the compressibility of binary mixtures using the Kawakita model. Microcrystalline cellulose (MCC) and L-alanine were compacted alone and mixed at different weight fractions. The volume reduction, as a function of the compaction pressure, was acquired during the compaction process ("in-die") and after elastic recovery ("out-of-die"). For the pure components, the Kawakita model is well suited to the description of the volume reduction. For binary mixtures, an original approach for the prediction of the volume reduction without using the effective Kawakita parameters was proposed and tested. The good agreement between experimental and predicted data proved that this model was efficient to predict the volume reduction of MCC and L-alanine mixtures during compaction experiments. Copyright © 2011 Elsevier B.V. All rights reserved.

A Variational Statistical-Field Theory for Polar Liquid Mixtures

NASA Astrophysics Data System (ADS)

Zhuang, Bilin; Wang, Zhen-Gang

Using a variational field-theoretic approach, we derive a molecularly-based theory for polar liquid mixtures. The resulting theory consists of simple algebraic expressions for the free energy of mixing and the dielectric constant as functions of mixture composition. Using only the dielectric constants and the molar volumes of the pure liquid constituents, the theory evaluates the mixture dielectric constants in good agreement with the experimental values for a wide range of liquid mixtures, without using adjustable parameters. In addition, the theory predicts that liquids with similar dielectric constants and molar volumes dissolve well in each other, while sufficient disparity in these parameters result in phase separation. The calculated miscibility map on the dielectric constant-molar volume axes agrees well with known experimental observations for a large number of liquid pairs. Thus the theory provides a quantification for the well-known empirical ``like-dissolves-like'' rule. Bz acknowledges the A-STAR fellowship for the financial support.

Silicon-based sleeve devices for chemical reactions

DOEpatents

Northrup, M. Allen; Mariella, Jr., Raymond P.; Carrano, Anthony V.; Balch, Joseph W.

1996-01-01

A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

Silicon-based sleeve devices for chemical reactions

DOEpatents

Northrup, M.A.; Mariella, R.P. Jr.; Carrano, A.V.; Balch, J.W.

1996-12-31

A silicon-based sleeve type chemical reaction chamber is described that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis. 32 figs.

Upcycling : converting waste plastics into paramagnetic, conducting, solid, pure carbon microspheres.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pol, V.

2010-06-15

The recent tremendous increase in the volume of waste plastics (WP) will have a harmful environmental impact on the health of living beings. Hundreds of years are required to degrade WP in atmospheric conditions. Hence, in coming years, in addition to traditional recycling services, innovative 'upcycling' processes are necessary. This article presents an environmentally benign, solvent-free autogenic process that converts various WP [low density polyethylene (LDPE), high density polyethylene (HDPE), polyethylene terephthalate (PET), polystyrene (PS), or their mixtures] into carbon microspheres (CMSs), an industrially significant, value-added product. The thermal dissociation of these individual or mixed WP in a closed reactormore » under autogenic pressure (1000 psi) produced dry, pure powder of CMSs. In this paper, the optimization of process parameters such as the effect of mixing of WP with other materials, and the role of reaction temperature and time are reported. Employing advanced analytical techniques, the atomic structure, composition, and morphology of as-obtained CMSs were analyzed. The room-temperature paramagnetism in CMSs prepared from waste LDPE, HDPE, and PS was further studied by electron paramagnetic resonance (EPR). The conducting and paramagnetic nature of CMSs holds promise for their potential applications in toners, printers, paints, batteries, lubricants, and tires.« less

Counterpropagating wave acoustic particle manipulation device for the effective manufacture of composite materials.

PubMed

Scholz, Marc-S; Drinkwater, Bruce W; Llewellyn-Jones, Thomas M; Trask, Richard S

2015-10-01

An ultrasonic assembly device exhibiting broadband behavior and a sacrificial plastic frame is described. This device is used to assemble a variety of microscopic particles differing in size, shape, and material into simple patterns within several host fluids. When the host fluid is epoxy, the assembled materials can be cured and the composite sample extracted from the sacrificial frame. The wideband performance means that within a single device, the wavelength can be varied, leading to control of the length scale of the acoustic radiation force field. We show that glass fibers of 50 μm length and 14 μm diameter can be assembled into a series of stripes separated by hundreds of microns in a time of 0.3 s. Finite element analysis is used to understand the attributes of the device which control its wideband characteristics. The bandwidth is shown to be governed by the damping produced by a combination of the plastic frame and the relatively large volume of the fluid particle mixture. The model also reveals that the acoustic radiation forces are a maximum near the substrate of the device, which is in agreement with experimental observations. The device is extended to 8-transducers and used to assemble more complex particle distributions.

A novel process for separation of polycarbonate, polyvinyl chloride and polymethyl methacrylate waste plastics by froth flotation.

PubMed

Wang, Chong-Qing; Wang, Hui; Huang, Luo-Luo

2017-07-01

A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO 4 ) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO 4 concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO 4 changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO 4 concentration 2mmolL -1 , treatment time 10min, temperature 60°C, stirring rate 300rpm, flotation time 1min and frother concentration 17.5mgL -1 . Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO 4 treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO 4 solution is feasible, enabling the process greener. Copyright © 2017 Elsevier Ltd. All rights reserved.

Storage of H.sub.2 by absorption and/or mixture within a fluid medium

DOEpatents

Berry, Gene David; Aceves, Salvador Martin

2007-03-20

For the first time, a hydrogen storage method, apparatus and system having a fluid mixture is provided. At predetermined pressures and/or temperatures within a contained substantially fixed volume, the fluid mixture can store a high density of hydrogen molecules, wherein a predetermined phase of the fluid mixture is capable of being withdrawn from the substantially fixed volume for use as a vehicle fuel or energy storage having reduced and/or eliminated evaporative losses, especially where storage weight, vessel cost, vessel shape, safety, and energy efficiency are beneficial.

Resident Exposure to Peripheral Nerve Surgical Procedures During Residency Training

PubMed Central

Gil, Joseph A.; Daniels, Alan H.; Akelman, Edward

2016-01-01

Background Variability in case exposures has been identified for orthopaedic surgery residents. It is not known if this variability exists for peripheral nerve procedures. Objective The objective of this study was to assess ACGME case log data for graduating orthopaedic surgery, plastic surgery, general surgery, and neurological surgery residents for peripheral nerve surgical procedures and to evaluate intraspecialty and interspecialty variability in case volume. Methods Surgical case logs from 2009 to 2014 for the 4 specialties were compared for peripheral nerve surgery experience. Peripheral nerve case volume between specialties was performed utilizing a paired t test, 95% confidence intervals were calculated, and linear regression was calculated to assess the trends. Results The average number of peripheral nerve procedures performed per graduating resident was 54.2 for orthopaedic surgery residents, 62.8 for independent plastic surgery residents, 84.6 for integrated plastic surgery residents, 22.4 for neurological surgery residents, and 0.4 for surgery residents. Intraspecialty comparison of the 10th and 90th percentile peripheral nerve case volume in 2012 revealed remarkable variability in training. There was a 3.9-fold difference within orthopaedic surgery, a 5.0-fold difference within independent plastic surgery residents, an 8.8-fold difference for residents from integrated plastic surgery programs, and a 7.0-fold difference within the neurological surgery group. Conclusions There is interspecialty and intraspecialty variability in peripheral nerve surgery volume for orthopaedic, plastic, neurological, and general surgery residents. Caseload is not the sole determinant of training quality as mentorship, didactics, case breadth, and complexity play an important role in training. PMID:27168883

Effects of Toxic Leachate from Commercial Plastics on Larval Survival and Settlement of the Barnacle Amphibalanus amphitrite.

PubMed

Li, Heng-Xiang; Getzinger, Gordon J; Ferguson, P Lee; Orihuela, Beatriz; Zhu, Mei; Rittschof, Daniel

2016-01-19

Plastic pollution represents a major and growing global problem. It is well-known that plastics are a source of chemical contaminants to the aquatic environment and provide novel habitats for marine organisms. The present study quantified the impacts of plastic leachates from the seven categories of recyclable plastics on larval survival and settlement of barnacle Amphibalanus (=Balanus) amphitrite. Leachates from plastics significantly increased barnacle nauplii mortality at the highest tested concentrations (0.10 and 0.50 m(2)/L). Hydrophobicity (measured as surface energy) was positively correlated with mortality indicating that plastic surface chemistry may be an important factor in the effects of plastics on sessile organisms. Plastic leachates significantly inhibited barnacle cyprids settlement on glass at all tested concentrations. Settlement on plastic surfaces was significantly inhibited after 24 and 48 h, but settlement was not significantly inhibited compared to the controls for some plastics after 72-96 h. In 24 h exposure to seawater, we found larval toxicity and inhibition of settlement with all seven categories of recyclable commercial plastics. Chemical analysis revealed a complex mixture of substances released in plastic leachates. Leaching of toxic compounds from all plastics should be considered when assessing the risks of plastic pollution.

Hydration of alcohol clusters in 1-propanol-water mixture studied by quasielastic neutron scattering and an interpretation of anomalous excess partial molar volume.

PubMed

Misawa, M; Inamura, Y; Hosaka, D; Yamamuro, O

2006-08-21

Quasielastic neutron scattering measurements have been made for 1-propanol-water mixtures in a range of alcohol concentration from 0.0 to 0.167 in mole fraction at 25 degrees C. Fraction alpha of water molecules hydrated to fractal surface of alcohol clusters in 1-propanol-water mixture was obtained as a function of alcohol concentration. Average hydration number N(ws) of 1-propanol molecule is derived from the value of alpha as a function of alcohol concentration. By extrapolating N(ws) to infinite dilution, we obtain values of 12-13 as hydration number of isolated 1-propanol molecule. A simple interpretation of structural origin of anomalous excess partial molar volume of water is proposed and as a result a simple equation for the excess partial molar volume is deduced in terms of alpha. Calculated values of the excess partial molar volumes of water and 1-propanol and the excess molar volume of the mixture are in good agreement with experimental values.

Effects of simulant mixed waste on EPDM and butyl rubber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nigrey, P.J.; Dickens, T.G.

1997-11-01

The authors have developed a Chemical Compatibility Testing Program for the evaluation of plastic packaging components which may be used in transporting mixed waste forms. In this program, they have screened 10 plastic materials in four liquid mixed waste simulants. These plastics were butadiene-acrylonitrile copolymer (Nitrile) rubber, cross-linked polyethylene, epichlorohydrin rubber, ethylene-propylene (EPDM) rubber, fluorocarbons (Viton and Kel-F{trademark}), polytetrafluoro-ethylene (Teflon), high-density polyethylene, isobutylene-isoprene copolymer (Butyl) rubber, polypropylene, and styrene-butadiene (SBR) rubber. The selected simulant mixed wastes were (1) an aqueous alkaline mixture of sodium nitrate and sodium nitrite; (2) a chlorinated hydrocarbon mixture; (3) a simulant liquid scintillation fluid; andmore » (4) a mixture of ketones. The screening testing protocol involved exposing the respective materials to approximately 3 kGy of gamma radiation followed by 14-day exposures to the waste simulants at 60 C. The rubber materials or elastomers were tested using Vapor Transport Rate measurements while the liner materials were tested using specific gravity as a metric. The authors have developed a chemical compatibility program for the evaluation of plastic packaging components which may be incorporated in packaging for transporting mixed waste forms. From the data analyses performed to date, they have identified the thermoplastic, polychlorotrifluoroethylene, as having the greatest chemical compatibility after having been exposed to gamma radiation followed by exposure to the Hanford Tank simulant mixed waste. The most striking observation from this study was the poor performance of polytetrafluoroethylene under these conditions. In the evaluation of the two elastomeric materials they have concluded that while both materials exhibit remarkable resistance to these environmental conditions, EPDM has a greater resistance to this corrosive simulant mixed waste.« less

Study of the elastic behavior of synthetic lightweight aggregates (SLAs)

NASA Astrophysics Data System (ADS)

Jin, Na

Synthetic lightweight aggregates (SLAs), composed of coal fly ash and recycled plastics, represent a resilient construction material that could be a key aspect to future sustainable development. This research focuses on a prediction of the elastic modulus of SLA, assumed as a homogenous and isotropic composite of particulates of high carbon fly ash (HCFA) and a matrix of plastics (HDPE, LDPE, PS and mixture of plastics), with the emphasis on SLAs made of HCFA and PS. The elastic moduli of SLA with variable fly ash volume fractions are predicted based on finite element analyses (FEA) performed using the computer programs ABAQUS and PLAXIS. The effect of interface friction (roughness) between phases and other computation parameters; e.g., loading strain, stiffness of component, element type and boundary conditions, are included in these analyses. Analytical models and laboratory tests provide a baseline for comparison. Overall, results indicate ABAQUS generates elastic moduli closer to those predicted by well-established analytical models than moduli predicted from PLAXIS, especially for SLAs with lower fly ash content. In addition, an increase in roughness, loading strain indicated increase of SLAs stiffness, especially as fly ash content increases. The elastic moduli obtained from unconfined compression generally showed less elastic moduli than those obtained from analytical and ABAQUS 3D predictions. This may be caused by possible existence of pre-failure surface in specimen and the directly interaction between HCFA particles. Recommendations for the future work include laboratory measurements of SLAs moduli and FEM modeling that considers various sizes and random distribution of HCFA particles in SLAs.

Shock compression response of model polymer/metal composites

NASA Astrophysics Data System (ADS)

Bober, David; Toyoda, Yoshi; Maddox, Brian; Barham, Matthew; Herbold, Eric; Gupta, Yogendra; Kumar, Mukul

2017-06-01

Heterogeneous materials do not respond mechanically to an impulse in the manner of homogeneous metals and alloys. The propagation of a wave in a microstructure with chemically distinct identities, that are only in incidental contact with each other, is a complex process and also poorly understood. Here we will report on a series of gas gun plate-impact experiments on a polymer-metal composite, where the volume fraction of the metallic phase is systematically varied from 0 to 40%, while other parameters like the sample thickness is kept a constant. A range of impact velocities was employed and the free surface velocity was interrogated to get a continuum measure of the internal materials processes. These results were then compared to the results of highly resolved mesoscale calculations to understand the wave propagation and visco-plastic effects that were observed in the experimental observations. The unfilled Si-polymer demonstrated a steady single wave shock response; whereas the wave profiles obtained from mixture samples showed structures at the onset of wave that depended on the volume fractio of the fill. This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

"Self-Shaping" of Multicomponent Drops.

PubMed

Cholakova, Diana; Valkova, Zhulieta; Tcholakova, Slavka; Denkov, Nikolai; Smoukov, Stoyan K

2017-06-13

In our recent study we showed that single-component emulsion drops, stabilized by proper surfactants, can spontaneously break symmetry and transform into various polygonal shapes during cooling [ Denkov Nature 2015 , 528 , 392 - 395 ]. This process involves the formation of a plastic rotator phase of self-assembled oil molecules beneath the drop surface. The plastic phase spontaneously forms a frame of plastic rods at the oil drop perimeter which supports the polygonal shapes. However, most of the common substances used in industry appear as mixtures of molecules rather than pure substances. Here we present a systematic study of the ability of multicomponent emulsion drops to deform upon cooling. The observed trends can be summarized as follows: (1) The general drop-shape evolution for multicomponent drops during cooling is the same as with single-component drops; however, some additional shapes are observed. (2) Preservation of the particle shape upon freezing is possible for alkane mixtures with chain length difference Δn ≤ 4; for greater Δn, phase separation within the droplet is observed. (3) Multicomponent particles prepared from alkanes with Δn ≤ 4 plastify upon cooling due to the formation of a bulk rotator phase within the particles. (4) If a compound, which cannot induce self-shaping when pure, is mixed with a certain amount of a compound which induces self-shaping, then drops prepared from this mixture can also self-shape upon cooling. (5) Self-emulsification phenomena are also observed for multicomponent drops. In addition to the three recently reported mechanisms of self-emulsification [ Tcholakova Nat. Commun. 2017 , ( 8 ), 15012 ], a new (fourth) mechanism is observed upon freezing for alkane mixtures with Δn > 4. It involves disintegration of the particles due to a phase separation of alkanes upon freezing.

Direct liquefaction of plastics and coprocessing of coal with plastics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huffman, G.P.; Feng, Z.; Mahajan, V.

1995-12-31

The objectives of this work were to optimize reaction conditions for the direct liquefaction of waste plastics and the coprocessing of coal with waste plastics. In previous work, the direct liquefaction of medium and high density polyethylene (PE), polypropylene (PPE), poly(ethylene terephthalate) (PET), and a mixed plastic waste, and the coliquefaction of these plastics with coals of three different ranks was studied. The results established that a solid acid catalyst (HZSM-5 zeolite) was highly active for the liquefaction of the plastics alone, typically giving oil yields of 80-95% and total conversions of 90-100% at temperatures of 430-450 {degrees}C. In themore » coliquefaction experiments, 50:50 mixtures of plastic and coal were used with a tetralin solvent (tetralin:solid = 3:2). Using approximately 1% of the HZSM-5 catalyst and a nanoscale iron catalyst, oil yields of 50-70% and total conversion of 80-90% were typical. In the current year, further investigations were conducted of the liquefaction of PE, PPE, and a commingled waste plastic obtained from the American Plastics Council (APC), and the coprocessing of PE, PPE and the APC plastic with Black Thunder subbituminous coal. Several different catalysts were used in these studies.« less

Plasma treatment of Seeds: effect on growth, spores and bacterial charge

NASA Astrophysics Data System (ADS)

Ambrico, P. F.; Simek, M.; Morano, M.; Ambrico, M.; Minafra, A.; Prukner, V.; de Miccolis Angelini, R. M.; Trotti, P.

2016-09-01

We report on the effect of low temperature plasma treatment on tomato, basil and tobacco commercial seeds. Seeds were treated in filtered ambient air volume, surface and plasma jet DBD at atmospheric pressure Sterile agar substrate, supplemented with a nutrient and vitamin mixture, was used to allow seeds germination in sterilized sealed plastic containers. The seeds were stored in controlled environmental condition (T = 26C, cycle of 14hrs light/10hrs dark condition). Since all the procedure was performed under sterile conditions, only bacteria and fungi carried by seeds could grow. Plasma treatment significantly reduced the presence of bacterial contamination, while some fungi could resist at shortest exposures Seeds germination was then followed by time lapse photography in sterile water on 3MM Whatman paper in a closed container. The effect of plasma treatment was a faster germination time of seeds and emergence of cotyledons, able to start photosynthesis in seedlings.The plasma treated seeds were also sow in a soil/peat moss mixture. Plants were cultivated for about 40 days, showing that plasma induced a faster growth in length and weight with respect to untreated seeds.Furthermore the effect of plasma on seeds surface was studied by SEM imaging. We acknowledge `SELGE' (Puglia) and TACR (TA03010098).

Recovery of PET from packaging plastics mixtures by wet shaking table.

PubMed

Carvalho, M T; Agante, E; Durão, F

2007-01-01

Recycling requires the separation of materials appearing in a mass of wastes of heterogeneous composition and characteristics, into single, almost pure, component/material flows. The separation of materials (e.g., some types of plastics) with similar physical properties (e.g., specific gravity) is often accomplished by human sorting. This is the case of the separation of packaging plastics in municipal solid wastes (MSW). The low cost of virgin plastics and low value of recycled plastics necessitate the utilization of low cost techniques and processes in the recycling of packaging plastics. An experimental study was conducted to evaluate the feasibility of production of a PET product, cleaned from PVC and PS, using a wet shaking table. The wet shaking table is an environmentally friendly process, widely used to separate minerals, which has low capital and operational costs. Some operational variables of the equipment, as well as different feed characteristics, were considered. The results show that the separation of these plastics is feasible although, similarly to the mineral field, in somewhat complex flow sheets.

Occurrence and sources of natural and anthropogenic lipid tracers in surface soils from arid urban areas of Saudi Arabia.

PubMed

Rushdi, Ahmed I; Al-Mutlaq, Khalid F; El-Mubarak, Aarif H; Al-Saleh, Mohammed A; El-Otaibi, Mubarak T; Ibrahim, Sami M M; Simoneit, Bernd R T

2016-01-01

Soil particles contain a variety of natural and anthropogenic organic components, and in urban areas can be considered as local collectors of pollutants. Surface soil samples were taken from ten urban areas in Riyadh during early winter of 2007. They were extracted with dichloromethane-methanol mixture and the extracts were analyzed by gas chromatography-mass spectrometry. The major compounds were unresolved complex mixture (UCM), plasticizers, n-alkanes, carbohydrates, n-alkanoic acids, hopanes, n-alkanols, and sterols. Vegetation detritus was the major natural source of organic compounds (24.0 ± 15.7%) in samples from areas with less human activities and included n-alkanes, n-alkanoic acids, n-alkanols, sterols and carbohydrates. Vehicular emission products and discarded plastics were the major anthropogenic sources in the soil particles (53.3 ± 21.3% and 22.7 ± 10.7%, respectively). The anthropogenic tracers were UCM, plasticizers, n-alkanes, hopanes and traces of steranes. Vegetation and human activities control the occurrence and distribution of natural and anthropogenic extractable organic matter in this arid urban area. Copyright © 2015 Elsevier Ltd. All rights reserved.

Doping control container for urine stabilization: a pilot study.

PubMed

Tsivou, Maria; Giannadaki, Evangelia; Hooghe, Fiona; Roels, Kris; Van Gansbeke, Wim; Garribba, Flaminia; Lyris, Emmanouil; Deventer, Koen; Mazzarino, Monica; Donati, Francesco; Georgakopoulos, Dimitrios G; Van Eenoo, Peter; Georgakopoulos, Costas G; de la Torre, Xavier; Botrè, Francesco

2017-05-01

Urine collection containers used in the doping control collection procedure do not provide a protective environment for urine, against degradation by microorganisms and proteolytic enzymes. An in-house chemical stabilization mixture was developed to tackle urine degradation problems encountered in human sport samples, in cases of microbial contamination or proteolytic activity. The mixture consists of antimicrobial substances and protease inhibitors for the simultaneous inactivation of a wide range of proteolytic enzymes. It has already been tested in lab-scale, as part of World Anti-Doping Agency's (WADA) funded research project, in terms of efficiency against microbial and proteolytic activity. The present work, funded also by WADA, is a follow-up study on the improvement of chemical stabilization mixture composition, application mode and limitation of interferences, using pilot urine collection containers, spray-coated in their internal surface with the chemical stabilization mixture. Urine in plastic stabilized collection containers have been gone through various incubation cycles to test for stabilization efficiency and analytical matrix interferences by three WADA accredited Laboratories (Athens, Ghent, and Rome). The spray-coated chemical stabilization mixture was tested against microorganism elimination and steroid glucuronide degradation, as well as enzymatic breakdown of proteins, such as intact hCG, recombinant erythropoietin and small peptides (GHRPs, ipamorelin), induced by proteolytic enzymes. Potential analytical interferences, observed in the presence of spray-coated chemical stabilization mixture, were recorded using routine screening procedures. The results of the current study support the application of the spray-coated plastic urine container, in the doping control collection procedure. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

An Investigation into the Properties and Microstructure of Cement Mixtures Modified with Cellulose Nanocrystal

PubMed Central

Flores, Jessica; Kamali, Mahsa; Ghahremaninezhad, Ali

2017-01-01

This paper aims to examine the effect of cellulose nanocrystals (CNC) on the hydration, transport behavior, and microstructure of cement mixtures. The addition of CNC delayed hydration at an early age but improved hydration at later ages. A small increase in the electrical resistivity of the cement mixtures with CNC was observed. Statistical nanoindentation showed a small tendency to a larger volume fraction of high density calcium-silicate-hydrate (C-S-H) and a smaller volume fraction of low-density C-S-H in the mixture with CNC. PMID:28772857

Comparison of the thermal stabilization of proteins by oligosaccharides and monosaccharide mixtures: Measurement and analysis in the context of excluded volume theory.

PubMed

Beg, Ilyas; Minton, Allen P; Islam, Asimul; Hassan, Md Imtaiyaz; Ahmad, Faizan

2018-06-01

The thermal stability of apo α-lactalbumin (α-LA) and lysozyme was measured in the presence of mixtures of glucose, fructose, and galactose. Mixtures of these monosaccharides in the appropriate stoichiometric ratio were found to have a greater stabilizing effect on each of the two proteins than equal weight/volume concentrations of di- tri- and tetrasaccharides with identical subunit composition (sucrose, trehalose, raffinose, and stachyose). The excluded volume model for the effect of a single saccharide on the stability of a protein previously proposed by Beg et al. [Biochemistry 54 (2015) 3594] was extended to treat the case of saccharide mixtures. The extended model predicts quantitatively the stabilizing effect of all monosaccharide mixtures on α-LA and lysozyme reported here, as well as previously published results obtained for ribonuclease A [Biophys. Chem. 138 (2008) 120] to within experimental uncertainty. Copyright © 2018 Elsevier B.V. All rights reserved.

Use of autologous and microsurgical breast reconstruction by U.S. plastic surgeons.

PubMed

Kulkarni, Anita R; Sears, Erika Davis; Atisha, Dunya M; Alderman, Amy K

2013-09-01

Concern exists that plastic surgeons are performing fewer autologous and microsurgical breast reconstructions, despite superior long-term outcomes. The authors describe the proportion of U.S. plastic surgeons performing these procedures and evaluate motivating factors and perceived barriers. A random national sample of American Society of Plastic Surgeons members was surveyed (n = 325; response rate, 76 percent). Surgeon and practice characteristics were assessed, and two multiple logistic regression models were created to evaluate factors associated with (1) high-volume autologous providers and (2) microsurgical providers. Qualitative assessments of motivating factors and barriers to microsurgery were also performed. Fewer than one-fifth of plastic surgeons perform autologous procedures for more than 50 percent of their breast cancer patients, and only one-quarter perform any microsurgical breast reconstruction. Independent predictors of a high-volume autologous practice include involvement with resident education (odds ratio, 2.57; 95 percent CI, 1.26 to 5.24) and a microsurgical fellowship (odds ratio, 2.09; 95 percent CI, 1.04 to 4.27). Predictors of microsurgical breast reconstruction include involvement with resident education (odds ratio, 6.8; 95 percent CI, 3.32 to 13.91), microsurgical fellowship (odds ratio, 2.4; 95 percent CI, 1.16 to 4.95), and high breast reconstruction volume (odds ratio, 6.68; 95 percent CI, 1.76 to 25.27). The primary motivator for microsurgery is superior outcomes, and the primary deterrents are time and reimbursement. The proportion of U.S. plastic surgeons with a high-volume autologous or microsurgical breast reconstruction practice is low. Involvement with resident education appears to facilitate both, whereas time constraints and reimbursement are primary deterrents. Future efforts should focus on improving the feasibility and accessibility of all types of breast reconstruction.

Development of pea protein-based bioplastics with antimicrobial properties.

PubMed

Perez-Puyana, Víctor; Felix, Manuel; Romero, Alberto; Guerrero, Antonio

2017-06-01

In the present work, bioplastics from renewable polymers were studied in order to reduce the huge generation of plastic wastes, causing an environmental problem that continues owing to the increasing demand for plastic products. Bioplastics with much better antimicrobial properties, in particular against Gram-positive bacteria, were obtained with the addition of nisin to the initial protein/plasticizer mixture. However, the addition of nisin produces more rigid but less deformable bioplastics (higher Young's modulus but lower strain at break). The results obtained are useful to demonstrate the antimicrobial properties of pea protein-based bioplastics by adding nisin and make them suitable as potential candidates to replace conventional plastics in food packaging. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Effect of compositional heterogeneity on dissolution of non-ideal LNAPL mixtures

NASA Astrophysics Data System (ADS)

Vasudevan, M.; Johnston, C. D.; Bastow, T. P.; Lekmine, G.; Rayner, J. L.; Nambi, I. M.; Suresh Kumar, G.; Ravi Krishna, R.; Davis, G. B.

2016-11-01

The extent of dissolution of petroleum hydrocarbon fuels into groundwater depends greatly on fuel composition. Petroleum fuels can consist of thousands of compounds creating different interactions within the non-aqueous phase liquid (NAPL), thereby affecting the relative dissolution of the components and hence a groundwater plume's composition over long periods. Laboratory experiments were conducted to study the variability in the effective solubilities and activity coefficients for common constituents of gasoline fuels (benzene, toluene, p-xylene and 1,2,4-trimethylbenzene) (BTX) in matrices with an extreme range of molar volumes and chemical affinities. Four synthetic mixtures were investigated comprising BTX with the bulk of the NAPL mixtures made up of either, ethylbenzene (an aromatic like BTX with similar molar volume); 1,3,5-trimethylbenzene (an aromatic with a greater molar volume); n-hexane (an aliphatic with a low molar volume); and n-decane (an aliphatic with a high molar volume). Equilibrium solubility values for the constituents were under-predicted by Raoult's law by up to 30% (higher experimental concentrations) for the mixture with n-hexane as a filler and over-predicted by up to 12% (lower experimental concentrations) for the aromatic mixtures with ethylbenzene and 1,3,5-trimethylbenzene as fillers. Application of PP-LFER (poly-parameter linear free energy relationship) model for non-ideal mixtures also resulted in poor correlation between experimentally measured and predicted concentrations, indicating that differences in chemical affinities can be the major cause of deviation from ideal behavior. Synthetic mixtures were compared with the dissolution behavior of fresh and naturally weathered unleaded gasoline. The presence of lighter aliphatic components in the gasoline had a profound effect on estimating effective solubility due to chemical affinity differences (estimated at 0.0055 per percentage increase in the molar proportion of aliphatic) as well as reduced molar volumes (estimated at - 0.0091 in the activity coefficient per unit increase in molar volume, mL/mol). Previously measured changes in activity coefficients due to natural weathering of 0.25 compares well to 0.27 calculated here based on changes in the chemical affinity and molar volumes. The study suggests that the initial estimation of the composition of a fuel is crucial in evaluating dissolution processes due to ideal and non-ideal dissolution, and in predicting long term dissolution trends and the longevity of NAPL petroleum plume risks.

Composite gel polymer electrolyte for lithium ion batteries

NASA Astrophysics Data System (ADS)

Naderi, Roya

Composite gel polymer electrolyte (CGPE) films, consisting of poly (vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) as the membrane, DMF and PC as solvent and plasticizing agent, mixture of charge modified TiO2 and SiO 2 nano particles as ionic conductors, and LiClO4+LiPF 6 as lithium salts were fabricated. Following the work done by Li et al., CGPE was coated on an O2-plasma treated trilayer polypropylene-polyethylene-polypropylene membrane separator using solution casting technique in order to improve the adhesive properties of gel polymer electrolyte to the separator membrane and its respective ionic conductivity due to decreasing the bulk resistance. In acidic CGPE with, the mixture of acid treated TiO2 and neutral SiO2 nano particles played the role of the charge modified nano fillers with enhanced hydroxyl groups. Likely, the mixture of neutral TiO 2 nano particles with basic SiO2 prepared through the hydrolization of tetraethyl orthosilicate (TEOS) provided a more basic environment due to the residues of NH4OH (Ammonium hydroxide) catalyst. The O2 plasma treated separator was coated with the solution of PVDF-HFP: modified nano fillers: Organic solvents with the mixture ratio of 0.1:0.01:1. After the evaporation of the organic solvents, the dried coated separator was soaked in PC-LiClO4+LiPF6 in EC: DMC:DEC (4:2:4 in volume) solution (300% wt. of PVDF-HFP) to form the final CGPE. Lim et al. has reported the enhanced ionic conductivity of 9.78*10-5 Scm-1 in an acidic composite polystyrene-Al2O3 solid electrolyte system with compared to that of basic and neutral in which the ionic conductivity undergoes an ion hopping process in solid interface rather than a segmental movement of ions through the plasticized polymer chain . Half-cells with graphite anode and Li metal as reference electrode were then assembled and the electrochemical measurements and morphology examinations were successfully carried out. Half cells demonstrated a considerable change in their electrochemical performance upon the enhancement of acidic properties of the CGPE, gaining the reversible specific capacity of 314 mAh.g-1 in acidic CGPE vs. 247 mAh.g-1 in basic CGPE C/20 after 33 cycles. The CGPE exhibited submicron pore size while the ionic conductivities were in order of 10-3 and 10-5 Scm-1 with and without modified nano-fillers respectively.

Forehead lift

MedlinePlus

... both sides even. If you have already had plastic surgery to lift your upper eyelids, a forehead ... brow lifting. In: Rubin JP, Neligan PC, eds. Plastic Surgery: Volume 2: Aesthetic Surgery . 4th ed. Philadelphia, ...

Economic analysis of the future growth of cosmetic surgery procedures.

PubMed

Liu, Tom S; Miller, Timothy A

2008-06-01

The economic growth of cosmetic surgical and nonsurgical procedures has been tremendous. Between 1992 and 2005, annual U.S. cosmetic surgery volume increased by 725 percent, with over $10 billion spent in 2005. It is unknown whether this growth will continue for the next decade and, if so, what impact it will it have on the plastic surgeon workforce. The authors analyzed annual U.S. cosmetic surgery procedure volume reported by the American Society of Plastic Surgeons (ASPS) National Clearinghouse of Plastic Surgery Statistics between 1992 and 2005. Reconstructive plastic surgery volume was not included in the analysis. The authors analyzed the ability of economic and noneconomic variables to predict annual cosmetic surgery volume. The authors also used growth rate analyses to construct models with which to predict the future growth of cosmetic surgery. None of the economic and noneconomic variables were a significant predictor of annual cosmetic surgery volume. Instead, based on current compound annual growth rates, the authors predict that total cosmetic surgery volume (surgical and nonsurgical) will exceed 55 million annual procedures by 2015. ASPS members are projected to perform 299 surgical and 2165 nonsurgical annual procedures. Non-ASPS members are projected to perform 39 surgical and 1448 nonsurgical annual procedures. If current growth rates continue into the next decade, the future demand in cosmetic surgery will be driven largely by nonsurgical procedures. The growth of surgical procedures will be met by ASPS members. However, meeting the projected growth in nonsurgical procedures could be a potential challenge and a potential area for increased competition.

Substituting energy crops with organic wastes and agro-industrial residues for biogas production.

PubMed

Schievano, Andrea; D'Imporzano, Giuliana; Adani, Fabrizio

2009-06-01

In this study, industrial and agro-industrial by-products and residues (BRs), animal manures (AMs), and various types of organic wastes (OWs) were analyzed to evaluate their suitability as substitutes for energy crops (ECs) in biogas production. A comparison between the costs of the volume of biogas that can be produced from each substrate was presented with respect to the prices of the substrates in the Italian market. Furthermore, four different feeding mixtures were compared with a mixture of EC and swine manure (Mixture A) used in a full-scale plant in Italy. Swine manure is always included as a basic substrate in the feeding mixtures, because many of the Italian biogas plants are connected to farms. When EC were partially substituted with BR (Mixture B), the cost (0.28 euro Nm(-3)) of the volume of biogas of Mixture A dropped to 0.18 euro Nm(-3). Furthermore, when the organic fraction of municipal solid waste (OFMSW) and olive oil sludge (OS) were used as possible solutions (Mixtures C and D), the costs of the volume of biogas were -0.20 and 0.11euroNm(-3), respectively. The negative price signifies that operators earn money for treating the waste. For the fifth mix (Mixture E) of the OFMSW with a high solid substrate, such as glycerin from biodiesel production, the resulting cost of the volume of biogas produced was -0.09 euro Nm(-3). By comparing these figures, it is evident that the biogas plants at farm level are good candidates for treating organic residues of both municipalities and the agro-industrial sector in a cost-effective way, and in providing territorially diffused electric and thermal power. This may represent a potential development for agrarian economy.

Co-pyrolysis characteristics and kinetic analysis of organic food waste and plastic.

PubMed

Tang, Yijing; Huang, Qunxing; Sun, Kai; Chi, Yong; Yan, Jianhua

2018-02-01

In this work, typical organic food waste (soybean protein (SP)) and typical chlorine enriched plastic waste (polyvinyl chloride (PVC)) were chosen as principal MSW components and their interaction during co-pyrolysis was investigated. Results indicate that the interaction accelerated the reaction during co-pyrolysis. The activation energies needed were 2-13% lower for the decomposition of mixture compared with linear calculation while the maximum reaction rates were 12-16% higher than calculation. In the fixed-bed experiments, interaction was observed to reduce the yield of tar by 2-69% and promote the yield of char by 13-39% compared with linear calculation. In addition, 2-6 times more heavy components and 61-93% less nitrogen-containing components were formed for tar derived from mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Separation of polar gases from nonpolar gases

DOEpatents

Kulprathipanja, S.

1986-08-19

The separation of polar gases from nonpolar gases may be effected by passing a mixture of nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The porous support is pretreated prior to casting of the mixture thereon by contact with a polyhydric alcohol whereby the pores of the support are altered, thus adding to the increased permeability of the polar gas.

PROCESS FOR PRODUCTION OF URANIUM

DOEpatents

Crawford, J.W.C.

1959-09-29

A process is described for the production of uranium by the autothermic reduction of an anhydrous uranium halide with an alkaline earth metal, preferably magnesium One feature is the initial reduction step which is brought about by locally bringing to reaction temperature a portion of a mixture of the reactants in an open reaction vessel having in contact with the mixture a lining of substantial thickness composed of calcium fluoride. The lining is prepared by coating the interior surface with a plastic mixture of calcium fluoride and water and subsequently heating the coating in situ until at last the exposed surface is substantially anhydrous.

Staged mold for encapsulating hazardous wastes

DOEpatents

Unger, Samuel L.; Telles, Rodney W.; Lubowitz, Hyman R.

1990-01-01

A staged mold for stabilizing hazardous wastes for final disposal by molding an agglomerate of the hazardous wastes and encapsulating the agglomerate. Three stages are employed in the process. In the first stage, a first mold body is positioned on a first mold base, a mixture of the hazardous wastes and a thermosetting plastic is loaded into the mold, the mixture is mechanically compressed, heat is applied to cure the mixture to form a rigid agglomerate, and the first mold body is removed leaving the agglomerate sitting on the first mold base. In the second stage, a clamshell second mold body is positioned around the agglomerate and the first mold base, a powdered thermoplastic resin is poured on top of the agglomerate and in the gap between the sides of the agglomerate and the second mold body, the thermoplastic is compressed, heat is applied to melt the thermoplastic, and the plastic is cooled jacketing the agglomerate on the top and sides. In the third stage, the mold with the jacketed agglomerate is inverted, the first mold base is removed exposing the former bottom of the agglomerate, powdered thermoplastic is poured over the former bottom, the first mold base is replaced to compress the thermoplastic, heat is applied to melt the new thermoplastic and the top part of the jacket on the sides, the plastic is cooled jacketing the bottom and fusing with the jacketing on the sides to complete the seamless encapsulation of the agglomerate.

Staged mold for encapsulating hazardous wastes

DOEpatents

Unger, Samuel L.; Telles, Rodney W.; Lubowitz, Hyman R.

1988-01-01

A staged mold for stabilizing hazardous wastes for final disposal by molding an agglomerate of the hazardous wastes and encapsulating the agglomerate. Three stages are employed in the process. In the first stage, a first mold body is positioned on a first mold base, a mixture of the hazardous wastes and a thermosetting plastic is loaded into the mold, the mixture is mechanically compressed, heat is applied to cure the mixture to form a rigid agglomerate, and the first mold body is removed leaving the agglomerate sitting on the first mold base. In the second stage, a clamshell second mold body is positioned around the agglomerate and the first mold base, a powdered thermoplastic resin is poured on top of the agglomerate and in the gap between the sides of the agglomerate and the second mold body, the thermoplastic is compressed, heat is applied to melt the thermoplastic, and the plastic is cooled jacketing the agglomerate on the top and sides. In the third stage, the mold with the jacketed agglomerate is inverted, the first mold base is removed exposing the former bottom of the agglomerate, powdered thermoplastic is poured over the former bottom, the first mold base is replaced to compress the thermoplastic, heat is applied to melt the new thermoplastic and the top part of the jacket on the sides, the plastic is cooled jacketing the bottom and fusing with the jacketing on the sides to complete the seamless encapsulation of the agglomerate.

Method for encapsulating hazardous wastes using a staged mold

DOEpatents

Unger, Samuel L.; Telles, Rodney W.; Lubowitz, Hyman R.

1989-01-01

A staged mold and method for stabilizing hazardous wastes for final disposal by molding an agglomerate of the hazardous wastes and encapsulating the agglomerate. Three stages are employed in the process. In the first stage, a first mold body is positioned on a first mold base, a mixture of the hazardous wastes and a thermosetting plastic is loaded into the mold, the mixture is mechanically compressed, heat is applied to cure the mixture to form a rigid agglomerate, and the first mold body is removed leaving the agglomerate sitting on the first mold base. In the second stage, a clamshell second mold body is positioned around the agglomerate and the first mold base, a powdered thermoplastic resin is poured on top of the agglomerate and in the gap between the sides of the agglomerate and the second mold body, the thermoplastic is compressed, heat is applied to melt the thermoplastic, and the plastic is cooled jacketing the agglomerate on the top and sides. In the third stage, the mold with the jacketed agglomerate is inverted, the first mold base is removed exposing the former bottom of the agglomerate, powdered thermoplastic is poured over the former bottom, the first mold base is replaced to compress the thermoplastic, heat is applied to melt the new thermoplastic and the top part of the jacket on the sides, the plastic is cooled jacketing the bottom and fusing with the jacketing on the sides to complete the seamless encapsulation of the agglomerate.

Description of plastic deformation of structural materials in triaxial loading

NASA Astrophysics Data System (ADS)

Lagzdins, A.; Zilaucs, A.

2008-03-01

A model of nonassociated plasticity is put forward for initially isotropic materials deforming with residual changes in volume under the action of triaxial normal stresses. The model is based on novel plastic loading and plastic potential functions, which define closed, convex, every where smooth surfaces in the 6D space of symmetric second-rank stress tensors. By way of example, the plastic deformation of a cylindrical concrete specimen wrapped with a CFRP tape and loaded in axial compression is described.

Silo discharge of binary granular mixtures.

PubMed

Madrid, M; Asencio, K; Maza, D

2017-08-01

We present numerical and experimental results on the mass flow rate during the discharge of three-dimensional silos filled with a bidisperse mixture of grains of different sizes. We analyzed the influence of the ratio between coarse and fine particles on the profile of volume fraction and velocity across the orifice. By using numerical simulations, we have shown that the velocity profile has the same shape as that in the monodisperse case and is insensitive to the composition of the mixture. On the contrary, the volume fraction profile is strongly affected by the composition of the mixture. Assuming that an effective particle size can be introduced to characterize the mixture, we have shown that previous expression for the mass flow rate of monodisperse particles can be used for binary mixtures. A comparison with Beverloo's correlation is also presented.

Excess Volumes and Excess Isentropic Compressibilities of Binary Liquid Mixtures of Trichloroethylene with Esters at 303.15 K

NASA Astrophysics Data System (ADS)

Ramanaiah, S.; Rao, C. Narasimha; Nagaraja, P.; Venkateswarlu, P.

2015-11-01

Exces volumes, VE, and excess isentropic compressibilities, κSE, have been reported as a function of composition for binary liquid mixtures of trichloroethylene with ethyl acetate, n-propyl acetate, and n-butyl acetate at 303.15 K. Isentropic compressibilities are calculated using measured sound speeds and density data for pure components and for binary mixtures. Excess volumes and excess isentropic compressibilities are found to be negative for the three systems studied over the entire composition range at 303.15 K, whereas these values become more negative with an increase of carbon chain length. The results are discussed in terms of intermolecular interactions between unlike molecules.

Cosmetic ear surgery

MedlinePlus

... ear reduction. In: Rubin JP, Neligan PC, eds. Plastic Surgery: Volume 2: Aesthetic Surgery . 4th ed. Philadelphia, ... Tang Ho, MD, Assistant Professor, Division of Facial Plastic and Reconstructive Surgery, Department of Otolaryngology – Head and ...

Partial Molar Volumes of 15-Crown-5 Ether in Mixtures of N,N-Dimethylformamide with Water.

PubMed

Tyczyńska, Magdalena; Jóźwiak, Małgorzata

2014-01-01

The density of 15-crown-5 ether (15C5) solutions in the mixtures of N,N -dimethylformamide (DMF) and water (H 2 O) was measured within the temperature range 293.15-308.15 K using an Anton Paar oscillatory U-tube densimeter. The results were used to calculate the apparent molar volumes ( V Φ ) of 15C5 in the mixtures of DMF + H 2 O over the whole concentration range. Using the apparent molar volumes and Redlich and Mayer equation, the standard partial molar volumes of 15-crown-5 were calculated at infinite dilution ([Formula: see text]). The limiting apparent molar expansibilities ( α ) were also calculated. The data are discussed from the point of view of the effect of concentration changes on interactions in solution.

Rational preparation of waste coal mixture for production of bricks by the method of compression molding

NASA Astrophysics Data System (ADS)

Stolboushkin, A. Yu; Ivanov, A. I.; Temlyantsev, M. V.; Fomina, O. A.

2016-10-01

Rational preparation of the mixture containing technogenic raw material - waste coal for the production of wall ceramics is developed. It was established that the technology of high-quality ceramic bricks requires: grinding of raw materials to class 0.3 + 0 mm, its aggregation in the intensive mixers into granules 1-3 mm, compression molding of adobe to plastic deformation of granules, drying and firing.

ENVIRONMENTAL ASSESSMENT OF A FIRETUBE BOILER FIRING COAL/OIL/WATER MIXTURES. VOLUME 1. TECHNICAL RESULTS

EPA Science Inventory

This volume describes emission results from sampling of flue gas from a firetube boiler burning a coal/oil/water (COW) mixture and COW with soda ash added (COW+SA) to control SO2 emissions. Measurements included: continuous monitoring of flue gas emissions; source assessment samp...

Noise Abatement

NASA Technical Reports Server (NTRS)

1983-01-01

SMART, Sound Modification and Regulated Temperature compound, is a liquid plastic mixture with exceptional energy and sound absorbing qualities. It is derived from a very elastic plastic which was an effective noise abatement material in the Apollo Guidance System. Discovered by a NASA employee, it is marketed by Environmental Health Systems, Inc. (EHS). The product has been successfully employed by a diaper company with noisy dryers and a sugar company with noisy blowers. The company also manufactures an audiometric test booth and acoustical office partitions.

Biofouling on buoyant marine plastics: An experimental study into the effect of size on surface longevity.

PubMed

Fazey, Francesca M C; Ryan, Peter G

2016-03-01

Recent estimates suggest that roughly 100 times more plastic litter enters the sea than is found floating at the sea surface, despite the buoyancy and durability of many plastic polymers. Biofouling by marine biota is one possible mechanism responsible for this discrepancy. Microplastics (<5 mm in diameter) are more scarce than larger size classes, which makes sense because fouling is a function of surface area whereas buoyancy is a function of volume; the smaller an object, the greater its relative surface area. We tested whether plastic items with high surface area to volume ratios sank more rapidly by submerging 15 different sizes of polyethylene samples in False Bay, South Africa, for 12 weeks to determine the time required for samples to sink. All samples became sufficiently fouled to sink within the study period, but small samples lost buoyancy much faster than larger ones. There was a direct relationship between sample volume (buoyancy) and the time to attain a 50% probability of sinking, which ranged from 17 to 66 days of exposure. Our results provide the first estimates of the longevity of different sizes of plastic debris at the ocean surface. Further research is required to determine how fouling rates differ on free floating debris in different regions and in different types of marine environments. Such estimates could be used to improve model predictions of the distribution and abundance of floating plastic debris globally. Copyright © 2016 Elsevier Ltd. All rights reserved.

High plastic concrete temperature specifications for paving mixtures.

DOT National Transportation Integrated Search

2011-08-01

This report documents a study performed for the Illinois Department of Transportation (IDOT) regarding : concrete roadway construction in hot weather. The main objective in this project is to develop improved : specifications and procedures with resp...

46 CFR 162.050-3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

...-water mixture to provide a resulting mixture that has an oil concentration of 15 ppm or less. Bilge alarm means an instrument that is designed to measure the oil content of oily mixtures from machinery... and oily mixtures combined with these residues. PPM means parts per million by volume of oil in water...

46 CFR 162.050-3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

...-water mixture to provide a resulting mixture that has an oil concentration of 15 ppm or less. Bilge alarm means an instrument that is designed to measure the oil content of oily mixtures from machinery... and oily mixtures combined with these residues. PPM means parts per million by volume of oil in water...

46 CFR 162.050-3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

...-water mixture to provide a resulting mixture that has an oil concentration of 15 ppm or less. Bilge alarm means an instrument that is designed to measure the oil content of oily mixtures from machinery... and oily mixtures combined with these residues. PPM means parts per million by volume of oil in water...

46 CFR 162.050-3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

...-water mixture to provide a resulting mixture that has an oil concentration of 15 ppm or less. Bilge alarm means an instrument that is designed to measure the oil content of oily mixtures from machinery... and oily mixtures combined with these residues. PPM means parts per million by volume of oil in water...

From Oil to Plastic. Young Discovery Library Series.

ERIC Educational Resources Information Center

Brice, Raphaelle

This book is written for children ages 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume explains in text and pictures how plastic is made from oil, the problems with this nearly indestructible material, and the future of plastics. Topics include: (1) formation of oil; (2) history of…

Plasticity and genetic adaptation mediate amphibian and reptile responses to climate change.

PubMed

Urban, Mark C; Richardson, Jonathan L; Freidenfelds, Nicole A

2014-01-01

Phenotypic plasticity and genetic adaptation are predicted to mitigate some of the negative biotic consequences of climate change. Here, we evaluate evidence for plastic and evolutionary responses to climate variation in amphibians and reptiles via a literature review and meta-analysis. We included studies that either document phenotypic changes through time or space. Plasticity had a clear and ubiquitous role in promoting phenotypic changes in response to climate variation. For adaptive evolution, we found no direct evidence for evolution of amphibians or reptiles in response to climate change over time. However, we found many studies that documented adaptive responses to climate along spatial gradients. Plasticity provided a mixture of adaptive and maladaptive responses to climate change, highlighting that plasticity frequently, but not always, could ameliorate climate change. Based on our review, we advocate for more experiments that survey genetic changes through time in response to climate change. Overall, plastic and genetic variation in amphibians and reptiles could buffer some of the formidable threats from climate change, but large uncertainties remain owing to limited data.

Plasticity and genetic adaptation mediate amphibian and reptile responses to climate change

PubMed Central

Urban, Mark C; Richardson, Jonathan L; Freidenfelds, Nicole A

2014-01-01

Phenotypic plasticity and genetic adaptation are predicted to mitigate some of the negative biotic consequences of climate change. Here, we evaluate evidence for plastic and evolutionary responses to climate variation in amphibians and reptiles via a literature review and meta-analysis. We included studies that either document phenotypic changes through time or space. Plasticity had a clear and ubiquitous role in promoting phenotypic changes in response to climate variation. For adaptive evolution, we found no direct evidence for evolution of amphibians or reptiles in response to climate change over time. However, we found many studies that documented adaptive responses to climate along spatial gradients. Plasticity provided a mixture of adaptive and maladaptive responses to climate change, highlighting that plasticity frequently, but not always, could ameliorate climate change. Based on our review, we advocate for more experiments that survey genetic changes through time in response to climate change. Overall, plastic and genetic variation in amphibians and reptiles could buffer some of the formidable threats from climate change, but large uncertainties remain owing to limited data. PMID:24454550

Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry.

PubMed

Wang, Chong-Qing; Wang, Hui; Liu, You-Nian

2015-01-01

Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by froth flotation combined with alkaline pretreatment was investigated for recycling industry. The effect of process variables was estimated by L9 (3(4)) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10 wt% sodium hydroxide, 20 min and 70°C. After alkaline pretreatment under optimum conditions, flotation separation PET from acrylonitrile-butadiene-styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of froth flotation and sink float separation was designed. This study facilitates industrial application of plastics flotation and provides technical insights into recycling of waste plastics. Copyright © 2014 Elsevier Ltd. All rights reserved.

Combination of three-stage sink-float method and selective flotation technique for separation of mixed post-consumer plastic waste.

PubMed

Pongstabodee, Sangobtip; Kunachitpimol, Napatr; Damronglerd, Somsak

2008-01-01

The aim of this research was to separate the different plastics of a mixed post-consumer plastic waste by the combination of a three-stage sink-float method and selective flotation. By using the three-stage sink-float method, six mixed-plastic wastes, belonging to the 0.3-0.5 cm size class and including high density polyethylene (HDPE), polypropylene (PP), polyvinylchloride (PVC), polystyrene (PS), polyethylene terephthalate (PET) and acrylonitrile-butadiene-styrene copolymers (ABS) were separated into two groups, i.e., a low density plastic group (HDPE and PP) and a high density plastic group (PET, PVC, PS and ABS) by tap water. Plastic whose density is less than that of the medium solution floats to the surface, while the one whose density is greater than that of the medium solution sinks to the bottom. The experimental results elucidated that complete separation of HDPE from PP was achieved by the three-stage sink-float method with 50% v/v ethyl alcohol. To succeed in the separation of a PS/ABS mixture from a PET/PVC mixture by the three-stage sink-float method, a 30% w/v calcium chloride solution was employed. To further separate post-consumer PET/PVC and PS/ABS based on plastic type, selective flotation was carried out. In order to succeed in selective flotation separation, it is necessary to render hydrophilic the surface of one or more species while the others are kept in a hydrophobic state. In flotation studies, the effects of wetting agent, frother, pH of solution and electrolyte on separation were determined. The selective flotation results showed that when using 500 mg l(-1) calcium lignosulfonate, 0.01 ppm MIBC, and 0.1 mg l(-1) CaCl2 at pH 11, PET could be separated from PVC. To separate ABS from PS, 200 mg l(-1) calcium lignosulfonate and 0.1 mg l(-1) CaCl2 at pH 7 were used as a flotation solution. Wettability of plastic increases when adding CaCl2 and corresponds to a decrease in its contact angles and to a reduction in the recovery of plastic in the floated product.

Toxicity of leachate from weathering plastics: An exploratory screening study with Nitocra spinipes.

PubMed

Bejgarn, Sofia; MacLeod, Matthew; Bogdal, Christian; Breitholtz, Magnus

2015-08-01

Between 60% and 80% of all marine litter is plastic. Leachate from plastics has previously been shown to cause acute toxicity in the freshwater species Daphnia magna. Here, we present an initial screening of the marine environmental hazard properties of leachates from weathering plastics to the marine harpacticoid copepod [Crustacea] Nitocra spinipes. Twenty-one plastic products made of different polymeric materials were leached and irradiated with artificial sunlight. Eight of the twenty-one plastics (38%) produced leachates that caused acute toxicity. Differences in toxicity were seen for different plastic products, and depending on the duration of irradiation. There was no consistent trend in how toxicity of leachate from plastics changed as a function of irradiation time. Leachate from four plastics became significantly more toxic after irradiation, two became significantly less toxic and two did not change significantly. Analysis of leachates from polyvinyl chloride (PVC) by liquid chromatography coupled to a full-scan high-resolution mass spectrometer showed that the leachates were a mixture of substances, but did not show evidence of degradation of the polymer backbone. This screening study demonstrates that leachates from different plastics differ in toxicity to N. spinipes and that the toxicity varies under simulated weathering. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Table and charts of equilibrium normal-shock properties for hydrogen-helium mixtures with velocities to 70 km/sec. Volume 1: 0.95 H2-0.05 He (by volume)

NASA Technical Reports Server (NTRS)

Miller, C. G., III; Wilder, S. E.

1976-01-01

Equilibrium thermodynamic and flow properties are presented in tabulated and graphical form for moving, standing, and reflected normal shock waves into hydrogen-helium mixtures representative of postulated outer planet atmospheres. These results are presented in four volumes and the volmetric compositions of the mixtures are 0.95H2-0.05He in Volume 1, 0.90H2-0.10He in Volume 2, 0.85H2-0.15He in Volume 3, and 0.75H2-0.25He in Volume 4. Properties include pressure, temperature, density, enthalpy, speed of sound, entropy, molecular-weight ratio, isentropic exponent, velocity, and species mole fractions. Incident (moving) shock velocities are varied from 4 to 70 km/sec for a range of initial pressure of 5 N/sq m to 100 kN/sq m. Results are applicable to shock-tube flows and for determining flow conditions behind the normal portion of the bow shock about a blunt body at high velocities in postulated outer planet atmospheres. The document is a revised version of the original edition of NASA SP-3085 published in 1974.

A hidden variable in shear transformation zone volume versus Poisson's ratio relation in metallic glasses

NASA Astrophysics Data System (ADS)

Kim, S. Y.; Oh, H. S.; Park, E. S.

2017-10-01

Herein, we elucidate a hidden variable in a shear transformation zone (STZ) volume (Ω) versus Poisson's ratio (ν) relation and clarify the correlation between STZ characteristics and the plasticity of metallic glasses (MGs). On the basis of cooperative shear model and atomic stress theories, we carefully formulate Ω as a function of molar volume (Vm) and ν. The twofold trend in Ω and ν is attributed to a relatively large variation of Vm as compared to that of ν as well as an inverse relation between Vm and ν. Indeed, the derived equation reveals that the number of atoms in an STZ instead of Ω is a microstructural characteristic which has a close relationship with plasticity since it reflects the preference of atomistic behaviors between cooperative shearing and the generation of volume strain fluctuation under stress. The results would deepen our understanding of the correlation between microscopic behaviors (STZ activation) and macroscopic properties (plasticity) in MGs and enable a quantitative approach in associating various STZ-related macroscopic behaviors with intrinsic properties of MGs.

Americium behaviour in plastic vessels.

PubMed

Legarda, F; Herranz, M; Idoeta, R; Abelairas, A

2010-01-01

The adsorption of (241)Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of (241)Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of (241)Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification. Copyright 2009 Elsevier Ltd. All rights reserved.

Influence of Cements Containing Calcareous Fly Ash as a Main Component Properties of Fresh Cement Mixtures

NASA Astrophysics Data System (ADS)

Gołaszewski, Jacek; Kostrzanowska-Siedlarz, Aleksandra; Ponikiewski, Tomasz; Miera, Patrycja

2017-10-01

The main goal of presented research was to examine usability of cements containing calcareous fly ash (W) from technological point of view. In the paper the results of tests concerning the influence of CEM II and CEM IV cements containing fly ash (W) on rheological properties, air content, setting times and plastic shrinkage of mortars are presented and discussed. Moreover, compatibility of plasticizers with cements containing fly ash (W) was also studied. Additionally, setting time and hydration heat of cements containing calcareous fly ash (W) were determined. In a broader aspect, the research contributes to promulgation of the possibility of using calcareous fly ash (W) in cement and concrete technology, what greatly benefits the environment protection (utilization of waste fly ash). Calcareous fly ash can be used successfully as the main component of cement. Cements produced by blending with processed fly ash or cements produced by interginding are characterized by acceptable technological properties. In respect to CEM I cements, cements containing calcareous fly ash worsen workability, decrease air content, delay setting time of mixtures. Cements with calcareous fly ash show good compatibility with plasticizers.

Extemporaneous sildenafil citrate oral suspensions for the treatment of pulmonary hypertension in children.

PubMed

Nahata, Milap C; Morosco, Richard S; Brady, Michael T

2006-02-01

The stability of sildenafil citrate 2.5 mg/mL in two extemporaneously prepared oral suspensions stored at 4 and 25 degrees C was studied. Thirty 25-mg tablets of sildenafil citrate were ground to powder, and the powder was combined with a 1:1 mixture of Ora-Sweet and Ora-Plus or a 1:1 mixture of methylcellulose 1% and Simple Syrup, NF, to produce two 2.5-mg/mL suspensions. Five plastic bottles of each suspension were stored in amber plastic prescription bottles at 4 or 25 degrees C. Samples were collected on days 0, 7, 14, 28, 42, 56, 70, and 91 for analysis of sildenafil content by high-performance liquid chromatography; pH was also measured. Samples were visually observed against black and white backgrounds. The mean concentration of sildenafil citrate exceeded 98% of the initial concentration in all samples at both temperatures throughout the 91-day study period. No changes in pH, odor, or physical appearance were observed. Sildenafil citrate 2.5 mg/mL in two extemporaneously compounded oral suspensions was stable for 91 days in plastic prescription bottles at 4 and 25 degrees C.

Thermo-acoustical molecular interaction study in binary mixtures of glycerol and ethylene glycol

NASA Astrophysics Data System (ADS)

Kaur, Kirandeep; Juglan, K. C.; Kumar, Harsh

2017-07-01

Ultrasonic velocity, density and viscosity are measured over the entire composition range for binary liquid mixtures of glycerol (CH2OH-CHOH-CH2OH) and ethylene glycol (HOCH2CH2OH) at different temperatures and constant frequency of 2MHz using ultrasonic interferometer, specific gravity bottle and viscometer respectively. Measured experimental values are used to obtained various acoustical parameters such as adiabatic compressibility, acoustic impedance, intermolecular free length, relaxation time, ultrasonic attenuation, effective molar weight, free volume, available volume, molar volume, Wada's constant, Rao's constant, Vander Waal's constant, internal pressure, Gibb's free energy and enthalpy. The variation in acoustical parameters are interpreted in terms of molecular interactions between the components of molecules of binary liquid mixtures.

Application of Liquid Paraffin in Castable CL-20-Based PBX

NASA Astrophysics Data System (ADS)

Zhang, Pu; Guo, Xue-Yong; Zhang, Jing-Yuan; Jiao, Qing-Jie

2014-10-01

Hydroxy-terminated polybutadiene (HTPB)/CL-20 castable explosives plasticized with liquid paraffin were processed successfully by a cast-curing method. The compatibility of liquid paraffin with CL-20, influence of liquid paraffin on CL-20 phase transition, and viscosity of the cast mixture were tested and analyzed. The thermal decomposition characteristics, thermal stability, mechanical sensitivity, and velocity of detonation (VOD) of the HTPB/CL-20 plastic-bonded explosives (PBXs) were also measured. The experimental results showed that liquid paraffin was well compatible with CL-20, and it did not have a distinct effect on the ɛ- to γ-phase transition of CL-20. In addition, the casting mixture was free-flowing with sufficiently low viscosity. When the content of CL-20 is 90% by weight, the measured VOD reached 8,775 m/s (density of 1.78 g/cm3), and the PBXs exhibited moderate mechanical sensitivity and good thermal stability.

Densities, Excess Molar Volumes, Viscosities, and Refractive Indices of Binary Mixtures of n-Butyl Acetate with 1-Chloroalkanes (C4-C8) at 298.15 K

NASA Astrophysics Data System (ADS)

Iloukhani, H.; Khanlarzadeh, K.; Rakhshi, M.

2011-03-01

Densities, viscosities, and refractive indices of binary mixtures of n-butyl acetate (1) +1-chlorobutane (2), +1-chloropentane (2), +1-chlorohexane (2), +1-chloroheptane (2), and +1-chlorooctane (2) were measured at 298.15 K for the liquid region and at ambient pressure for the whole composition range. The excess molar volumes V E were calculated from experimental densities. McAllister's three-body interaction, and Hind and Grunberg-Nissan models are used for correlating the viscosity of binary mixtures. The experimental data of binaries are analyzed to discuss the nature and strength of intermolecular interactions in these mixtures.

Method of testing gas insulated systems for the presence of conducting particles utilizing a gas mixture of nitrogen and sulfur hexafluoride

DOEpatents

Wootton, Roy E.

1979-01-01

A method of testing a gas insulated system for the presence of conducting particles. The method includes inserting a gaseous mixture comprising about 98 volume percent nitrogen and about 2 volume percent sulfur hexafluoride into the gas insulated system at a pressure greater than 60 lb./sq. in. gauge, and then applying a test voltage to the system. If particles are present within the system, the gaseous mixture will break down, providing an indicator of the presence of the particles.

Plastic-Syringe Induced Silicone Contamination in Organic Photvoltaic Fabrication: Implications for Small-Volume Additives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carr, John A.; Nalwa, Kanwar S.; Mahadevapuram, Rakesh

Herein, the implications of silicone contamination found in solution-processed conjugated polymer solar cells are explored. Similar to a previous work based on molecular cells, we find this contamination as a result of the use of plastic syringes during fabrication. However, in contrast to the molecular case, we find that glass-syringe fabricated devices give superior performance than plastic-syringe fabricated devices in poly(3-hexylthiophene)-based cells. We find that the unintentional silicone addition alters the solution’s wettability, which translates to a thinner, less absorbent film on spinning. With many groups studying the effects of small-volume additives, this work should be closely considered as manymore » of these additives may also directly alter the solutions’ wettability, or the amount of silicone dissolved off the plastic syringes, or both. Thereby, film thickness, which generally is not reported in detail, can vary significantly from device to device.« less

Storage of nitroglycerin (NTG) admixed with HBOC-201 for 30 days in polyolefin plastic bags: a pilot study.

PubMed

Nigam, Savita; McCarron, Richard; Arnaud, Francoise

2017-10-01

Hemorrhaged animals have benefited from resuscitation with the hemoglobin-based oxygen carrier (HBOC-201). Co-infusion of nitric oxide (NO) via separate intravascular lines is effective in attenuating HBOC-induced elevation of blood pressure. We tested whether nitroglycerin (NTG) and HBOC-201 can be packaged together as a single drug for resuscitation. Since NTG binds easily to plastics such as polyvinylchloride, we assessed the stability of this combination in oxygen barrier double-layer ethylene-vinyl alcohol/polyolefin bags over a 30-day period. Outcome measures indicative of the stability of HBOC/NTG were reported as changes in levels of hemoglobin (Hb), methemoglobin (MetHb), NTG, and nitrite over time. Individual tightly sealed small aliquots of HBOC/NTG were prepared under nitrogen and analyzed in a timely fashion from 0 to 30 days using hematology instruments, HPLC, FPLC, and chemiluminescence. The level of NTG in the HBOC/NTG mixture was reduced significantly over time whereas it was stable in control mixtures of NTG/saline. The level of total Hb in the HBOC/NTG and HBOC/saline mixtures remained stable over time. MetHb formed and increased to 6% up to day 1 and then slowly decreased in the HBOC/NTG mixture whereas it remained unchanged in the HBOC/saline mixture. Nitrite was produced in the HBOC/NTG group upon mixing, was increased at day 1, and then became undetectable. The reaction between HBOC-201 and NTG occurring upon mixing and developing over time in polyolefin bags makes the long-term storage of this mixed combination inappropriate.

Predicting melt rheology for hot-melt extrusion by means of a simple Tg-measurement.

PubMed

Bochmann, Esther S; Üstüner, Elgin E; Gryczke, Andreas; Wagner, Karl G

2017-10-01

The feasibility of predicting melt rheology by using the glass transition temperature (T g ) of a desired amorphous solid dispersion (ASD) for hot-melt extrusion (HME) and other melt based processes is presented. Three groups of three different active pharmaceutical ingredients (APIs) or plasticizer/copovidone mixtures, with identical glass transition in rheological testing, were used. Their rheological behavior as a function of temperature and frequency were analyzed by means of small amplitude oscillatory shear (SAOS) on an oscillatory rheometer. The zero-shear viscosity (η 0 ) identified at 150°C was compared to T g , measured by differential scanning calorimetry (DSC) and SAOS. A strong correlation between η 0 and T g was identified, independent of the API or plasticizer used to achieve T g of the mixture. To evaluate and rate the discrepancy in η 0 of the different mixtures at same T g , hot-melt extrusion trials were conducted to measure torque and mean residence time. In this paper, carbamazepine, dipyridamole, indomethacin, ibuprofen, polyethylene glycol (PEG 1500) in vinylpyrrolidone-vinyl acetate copolymer (copovidone) as matrix polymer were used. Copyright © 2017. Published by Elsevier B.V.

Mixture Toxicity of Nickel and Microplastics with Different Functional Groups on Daphnia magna.

PubMed

Kim, Dokyung; Chae, Yooeun; An, Youn-Joo

2017-11-07

In recent years, discarded plastic has become an increasingly prevalent pollutant in aquatic ecosystems. These plastic wastes decompose into microplastics, which pose not only a direct threat to aquatic organisms but also an indirect threat via adsorption of other aquatic pollutants. In this study, we investigated the toxicities of variable and fixed combinations of two types of microplastics [one coated with a carboxyl group (PS-COOH) and the other lacking this functional group (PS)] with the heavy metal nickel (Ni) on Daphnia magna and calculated mixture toxicity using a toxic unit model. We found that toxicity of Ni in combination with either of the two microplastics differed from that of Ni alone. Furthermore, in general, we observed that immobilization of D. magna exposed to Ni combined with PS-COOH was higher than that of D. magna exposed to Ni combined with PS. Collectively, the results of our study indicate that the toxic effects of microplastics and pollutants may vary depending on the specific properties of the pollutant and microplastic functional groups, and further research on the mixture toxicity of various combinations of microplastics and pollutants is warranted.

Tamping Mortars with Stabilizing and Plasticizing Admixtures

NASA Astrophysics Data System (ADS)

Terlyha, Volodymir; Sobol, Khrystyna

2012-06-01

Boreholes cementing operations at the depth of several kilometers requires the best technology as well as the best materials. To produce the materials satisfying all the requirements concerning the tamping works is possible using the technology of dry building mixes (DBM) prepared at the factories by thorough mixing of accurately dosed components. Using of chemical admixtures allows improving some properties of these mixes. In this work the influence of mineral fillers and chemical admixtures on the properties of the fresh mixture and hardened tamping mortar was investigated. It is established that introduction of the admixture with complex action on the basis of stabilizer Walocel 15-01 and plasticizer Melflux 2651 allows obtaining the fresh mixture with high spreadability. At the same time the value of dehydration approaches to zero which favorably effects on stabilization of fresh mixture and not allows the sedimentation processes to take place. By the X-ray analysis, the positive influence of modification admixtures on the hydration processes in the tamping mortars by activating them was identified. In the result of this, the formation of hydrate phases is accelerated; these phases tightly mud the pore area of tamping stone increasing by this its strength.

Recovery of spiked Δ9-tetrahydrocannabinol in oral fluid from polypropylene containers.

PubMed

Molnar, Anna; Lewis, John; Fu, Shanlin

2013-04-10

Oral fluid is currently used by Australian and international law enforcement agencies and employers to detect recent use of cannabis and other drugs of abuse. The main psychoactive constituent of cannabis, Δ(9)-tetrahydrocannabinol (THC), is highly lipophilic and losses occur when in contact with plastic, possibly due to its adsorption onto the plastic surface. This study aims to investigate factors governing the interaction of THC with plastic and search for ways of overcoming such interaction so to improve THC recovery. As polypropylene is one of the most common types of plastic used in collection devices, it was the focus of this study. All experiments were done by preparing neat oral fluid samples spiked with THC in 2-mL polypropylene centrifuge tubes. Samples were transferred with or without prior addition of Triton(®) X-100 (0.25%) to glass tubes containing d3-THC as internal standard and 0.1M phosphate buffer was then added. Samples were extracted by liquid-liquid extraction using hexane/ethyl acetate (9:1, v/v), dried and analysed by gas chromatography-mass spectrometry (GC-MS) after derivatisation. No significant difference was found in terms of THC loss to plastic when the concentration ranged from 25 to 1000 ng/mL in the same volume of oral fluid. Varying the oral fluid volume (0.5-1.5 mL) while keeping THC at a constant concentration showed an upward trend with more loss associated with lower volumes. The use of Triton(®) X-100 significantly decreased the adherence of THC to the plastic tubes and increased the THC transfer (>96%) at all volumes tested. Degradation of THC during storage was also studied over a 4-week period and it was found that azide did not seem to play a significant role in preserving THC in oral fluid. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Glass Transition Temperature of Saccharide Aqueous Solutions Estimated with the Free Volume/Percolation Model.

PubMed

Constantin, Julian Gelman; Schneider, Matthias; Corti, Horacio R

2016-06-09

The glass transition temperature of trehalose, sucrose, glucose, and fructose aqueous solutions has been predicted as a function of the water content by using the free volume/percolation model (FVPM). This model only requires the molar volume of water in the liquid and supercooled regimes, the molar volumes of the hypothetical pure liquid sugars at temperatures below their pure glass transition temperatures, and the molar volumes of the mixtures at the glass transition temperature. The model is simplified by assuming that the excess thermal expansion coefficient is negligible for saccharide-water mixtures, and this ideal FVPM becomes identical to the Gordon-Taylor model. It was found that the behavior of the water molar volume in trehalose-water mixtures at low temperatures can be obtained by assuming that the FVPM holds for this mixture. The temperature dependence of the water molar volume in the supercooled region of interest seems to be compatible with the recent hypothesis on the existence of two structure of liquid water, being the high density liquid water the state of water in the sugar solutions. The idealized FVPM describes the measured glass transition temperature of sucrose, glucose, and fructose aqueous solutions, with much better accuracy than both the Gordon-Taylor model based on an empirical kGT constant dependent on the saccharide glass transition temperature and the Couchman-Karasz model using experimental heat capacity changes of the components at the glass transition temperature. Thus, FVPM seems to be an excellent tool to predict the glass transition temperature of other aqueous saccharides and polyols solutions by resorting to volumetric information easily available.

Foam imbibition in a Hele-Shaw cell via laminated microfluidic ``T-junction'' device

NASA Astrophysics Data System (ADS)

Parra, Dina; Ward, Thomas

2013-11-01

In this talk we analyze experimental results of a novel microfluidic ``T-junction'' device, made from laminated plastic, that is used to produce foam in porous media. The fluids, both Newtonian and non-Newtonian liquids and air, are driven using constant-static pressure fluid pumping. For the T-junction geometry studied there are novel observations with this type of pumping: 1) at low pressure ratios there is an increase in the liquid and total flow rates and 2) at higher pressure ratios there is a decrease in the liquid flow rate. To understand this phenomenon we visualize the drop production process near the T-junction. Furthermore, flow rates for the liquid and total volume are estimated by imbibing the foam into a Hele-Shaw cell. Foam is produced by using a mixture containing aqueous polyacrylamide of concentrations ranging from 0.01-0.10% by weight and several solution also containing a sodium-lauryl-sulfate (SLS) surfactant at concentrations ranging 0.01-0.1% by weight.

Temperature control apparatus

DOEpatents

Northrup, M. Allen

2003-08-05

A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and non-silicon based materials to provide the thermal properties desired. For example, the chamber may combine a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

Reactor antineutrino detector iDREAM.

NASA Astrophysics Data System (ADS)

Gromov, M. B.; Lukyanchenko, G. A.; Novikova, G. J.; Obinyakov, B. A.; Oralbaev, A. Y.; Skorokhvatov, M. D.; Sukhotin, S. V.; Chepurnov, A. S.; Etenko, A. V.

2017-09-01

Industrial Detector for Reactor Antineutrino Monitoring (iDREAM) is a compact (≈ 3.5m 2) industrial electron antineutrino spectrometer. It is dedicated for remote monitoring of PWR reactor operational modes by neutrino method in real-time. Measurements of antineutrino flux from PWR allow to estimate a fuel mixture in active zone and to check the status of the reactor campaign for non-proliferation purposes. LAB-based gadolinium doped scintillator is exploited as a target. Multizone architecture of the detector with gamma-catcher surrounding fiducial volume and plastic muon veto above and below ensure high efficiency of IBD detection and background suppression. DAQ is based on Flash ADC with PSD discrimination algorithms while digital trigger is programmable and flexible due to FPGA. The prototype detector was started up in 2014. Preliminary works on registration Cerenkov radiation produced by cosmic muons were established with distilled water inside the detector in order to test electronic and slow control systems. Also in parallel a long-term measurements with different scintillator samples were conducted.

Microfabricated sleeve devices for chemical reactions

DOEpatents

Northrup, M. Allen

2003-01-01

A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and non-silicon based materials to provide the thermal properties desired. For example, the chamber may combine a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

On Technological Properties of Modified Epoxy Composites

NASA Astrophysics Data System (ADS)

Gavrilov, M.

2017-11-01

The technological properties of epoxy composite materials based on constructional and chemical waste have been reviewed. The viscosity and component wettability of modified epoxy composites have been researched. The use of plasticizing additives to improve mixtures forming has been justified.

Biodegradable films from isolate of sunflower (Helianthus annuus) proteins.

PubMed

Ayhllon-Meixueiro, F; Vaca-Garcia, C; Silvestre, F

2000-07-01

The film-forming potential of isolate of sunflower proteins (ISFP) was investigated. Homogeneous films were obtained by dissolution of ISFP in alkaline water (pH 12), addition of a plasticizer, casting, and drying. Maximum protein solubilization and unfolding led to films with the highest elasticity. The effects of five dissolving bases and five plasticizers on the mechanical properties were studied. The use of ionic bases (LiOH, NaOH) capable of interfering with the interproteic noncovalent bonds resulted in the greatest tensile strength (sigma(max)) and elongation at break (epsilon(max)) values (3.9 MPa and 215-251%, respectively). Plasticizers conferred diverse tensile properties to the films: the use of 1,3-propanediol resulted in the highest sigma(max) (27.1 MPa), and glycerol resulted in the greatest epsilon(max) (251%). Different mechanical properties were obtained by using mixtures of these plasticizers.

Volume growth of pine and hardwood in uneven-aged loblolly pine-upland hardwood mixtures

Treesearch

Robert M. Farrar; Paul A. Murphy; Daniel J. Leduc

1989-01-01

Results are reported from an exploratory investigation of stand-level periodic volume growth of uneven-aged mixed loblolly pine (Pinus taeda L.)-upland hardwood stands on good sites in southeastern Arkansas. A restricted set of replicated observations was extracted from an extensive CFI database involving varying pine-hardwood mixtures to form an array of plots with...

ENVIRONMENTAL ASSESSMENT OF A FIRETUBE BOILER FIRING COAL/OIL/WATER MIXTURES. VOLUME 2. DATA SUPPLEMENT

EPA Science Inventory

This volume is a compendium of detailed emission and test data from field tests of a firetube industrial boiler burning a coal/oil/water (COW) mixture. The boiler was tested while burning COW fuel, and COW with soda ash added (COW+SA) to serve as an SO2 sorbent. The test data inc...

Study on the Characteristics of a Scintillator for Beta-ray Detection using Epoxy Resin

NASA Astrophysics Data System (ADS)

Nam, Jong Soo; Choi, Yong Seok; Hong, Sang Bum; Seo, Bum Kyung; Moon, Jei Kwon; Choi, Jong Won

2017-09-01

A thin plate of a plastic scintillator for detecting a beta-ray was developed. The plastic scintillator was made using epoxy resin and organic scintillators such as 2.5-diphenyloxazole (PPO) and 1,4-bis [5-phenyl-2-oxazole] benzene (POPOP). The mixture ratio of epoxy resin and the organic scintillators was determined using their absorbance, transmittance, emission spectra, and transparency. Their optimal weight percentage of PPO and POPOP in the organic scintillators was adjusted to 0.2 wt%:0.01 wt%. The prepared plastic scintillator was used to measure the standard source of Sr-90. The pulse height spectra and total counts of the prepared plastic scintillator were similar to a commercial plastic scintillator. Based on the above results, a large-area plastic scintillator was prepared for rapid investigation of a site contaminated with Sr-90. The prepared large-area plastic scintillator was evaluated for the characteristics in the laboratory. The evaluation results are expected to be usefully utilized in the development of a large-area plastic scintillation detector. The large-area plastic scintillation detector developed on the basis of the evaluation results is expected to be utilized to quickly measure the contamination of Sr-90 in the grounds used as a nuclear power facility.

Temperature Dependence of Densities and Excess Molar Volumes of the Ternary Mixture (1-Butanol + Chloroform + Benzene) and its Binary Constituents (1-Butanol + Chloroform and 1-Butanol + Benzene)

NASA Astrophysics Data System (ADS)

Smiljanić, Jelena D.; Kijevčanin, Mirjana Lj.; Djordjević, Bojan D.; Grozdanić, Dušan K.; Šerbanović, Slobodan P.

2008-04-01

Densities ρ of the 1-butanol + chloroform + benzene ternary mixture and the 1-butanol + chloroform and 1-butanol + benzene binaries have been measured at six temperatures (288.15, 293.15, 298.15, 303.15, 308.15, and 313.15) K and atmospheric pressure, using an oscillating U-tube densimeter. From these densities, excess molar volumes ( V E) were calculated and fitted to the Redlich Kister equation for all binary mixtures and to the Nagata and Tamura equation for the ternary system. The Radojković et al. equation has been used to predict excess molar volumes of the ternary mixtures. Also, V E data of the binary systems were correlated by the van der Waals (vdW1) and Twu Coon Bluck Tilton (TCBT) mixing rules coupled with the Peng Robinson Stryjek Vera (PRSV) equation of state. The prediction and correlation of V E data for the ternary system were performed by the same models.

Mixture design of rice flour, maize starch and wheat starch for optimization of gluten free bread quality.

PubMed

Mancebo, Camino M; Merino, Cristina; Martínez, Mario M; Gómez, Manuel

2015-10-01

Gluten-free bread production requires gluten-free flours or starches. Rice flour and maize starch are two of the most commonly used raw materials. Over recent years, gluten-free wheat starch is available on the market. The aim of this research was to optimize mixtures of rice flour, maize starch and wheat starch using an experimental mixture design. For this purpose, dough rheology and its fermentation behaviour were studied. Quality bread parameters such as specific volume, texture, cell structure, colour and acceptability were also analysed. Generally, starch incorporation reduced G* and increased the bread specific volume and cell density, but the breads obtained were paler than the rice flour breads. Comparing the starches, wheat starch breads had better overall acceptability and had a greater volume than maize-starch bread. The highest value for sensorial acceptability corresponded to the bread produced with a mixture of rice flour (59 g/100 g) and wheat starch (41 g/100 g).

Numerical Implementation of the Cohesive Soil Bounding Surface Plasticity Model. Volume I.

DTIC Science & Technology

1983-02-01

AD-R24 866 NUMERICAL IMPLEMENTATION OF THE COHESIVE SOIL BOUNDING 1/2 SURFACE PLASTICITY ..(U) CALIFORNIA UNIV DAVIS DEPT OF CIVIL ENGINEERING L R...a study of various numerical means for implementing the bounding surface plasticity model for cohesive soils is presented. A comparison is made of... Plasticity Models 17 3.4 Selection Of Methods For Comparison 17 3.5 Theory 20 3.5.1 Solution Methods 20 3.5.2 Reduction Of The Number Of Equation

Analysis of non-phthalates plasticizers on porous graphitic carbon by supercritical fluid chromatography using evaporative light scattering detection.

PubMed

Vaccher, Claude; Decaudin, Bertrand; Sautou, Valérie; Lecoeur, Marie

2014-09-12

The analysis of several plasticizers, widely used in the production of medical devices, was investigated on porous graphitic carbon (PGC) stationary phase in supercritical fluid chromatography (SFC) with an evaporative light scattering detector (ELSD). Due to strong interaction of compounds with the PGC support, solvents of strong eluotropic strength were added to the CO2 supercritical fluid. The effect of alkyl chain (pentane, hexane, heptane) and chlorinated (CH2Cl2, CHCl3, CCl4) solvents was studied on the retention and on the ELSD detection of plasticizers. A co-solvent mixture composed of CHCl3/heptane, eluted under gradient mode, allowed a significant improvement of the ELSD response compared to the use of each solvent individually. Then, a central composite design (CCD) was implemented to optimize both the separation and the detection of plasticizers. The parameters involved were the outlet pressure, the gradient slope, the co-solvent composition and the drift tube temperature of the ELSD. After optimization, baseline separation of plasticizers was achieved in 7min and best signal-to-noise ratios were obtained with outlet pressure and drift tube temperature of ELSD set at 200bar and 31°C, respectively. The co-solvent mixture was also composed of CHCl3/heptane (35/65 v/v) and a gradient from 15 to 60% of co-solvent in 2.2min was employed. The results demonstrated that CCD is a powerful tool for the optimization of SFC/ELSD method and the response surface model analysis can provide statistical understandings of the significant factors required to achieve optimal separation and ELSD sensitivity. Copyright © 2014 Elsevier B.V. All rights reserved.

Additives in plastics.

PubMed Central

Deanin, R D

1975-01-01

The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

Applications and societal benefits of plastics.

PubMed

Andrady, Anthony L; Neal, Mike A

2009-07-27

This article explains the history, from 1600 BC to 2008, of materials that are today termed 'plastics'. It includes production volumes and current consumption patterns of five main commodity plastics: polypropylene, polyethylene, polyvinyl chloride, polystyrene and polyethylene terephthalate. The use of additives to modify the properties of these plastics and any associated safety, in use, issues for the resulting polymeric materials are described. A comparison is made with the thermal and barrier properties of other materials to demonstrate the versatility of plastics. Societal benefits for health, safety, energy saving and material conservation are described, and the particular advantages of plastics in society are outlined. Concerns relating to littering and trends in recycling of plastics are also described. Finally, we give predictions for some of the potential applications of plastic over the next 20 years.

An Experimental Study of High Strength-High Volume Fly Ash Concrete for Sustainable Construction Industry

NASA Astrophysics Data System (ADS)

Kate, Gunavant K.; Thakare, Sunil B., Dr.

2017-08-01

Concrete is the most widely used building material in the construction of infrastructures such as buildings, bridges, highways, dams, and many other facilities. This paper reports the development, the basic idea, the main properties of high strength-high volume fly ash with application in concrete associated with the development and implementation of Sustainable Properties of High Volume Fly Ash Concrete (HVFAC) Mixtures and Early Age Shrinkage and mechanical properties of concrete for 7,28,56 and 90days. Another alternative to make environment-friendly concrete is the development of high strength-high-volume fly ash concrete which is an synthesized from materials of geological origin or by-product materials such as fly ash which is rich in silicon and aluminum. In this paper 6 concrete mixtures were produced to evaluate the effect of key parameters on the mechanical properties of concrete and its behavior. The study key parameters are; binder material content, cement replacement ratios, and the steel fibers used to High Volume Fly Ash mixtures for increasing performance of concrete.

New plastic recycling technology

EPA Science Inventory

Greater than 60% of the total plastic content of municipal solid waste is comprised of polyolefins (high-density, low-density, and linear polyethylene and polypropylene. Polyethylene (PE) is the largest-volume component but presents a challenge due to the absence of low-energy de...

Novel phosphonates triazine derivative as economic flame retardant for cotton

USDA-ARS?s Scientific Manuscript database

Phosphorous-containing flame retardants are widely used in standard and engineering plastics, polyurethane foams, thermosets, coatings, and textiles. Organophosphorous flame retardants have been known to be more effective when used in conjunction with nitrogen-containing systems. Their mixture produ...

Study on Conversion of Municipal Plastic Wastes into Liquid Fuel Compounds, Analysis of Crdi Engine Performance and Emission Characteristics

NASA Astrophysics Data System (ADS)

Divakar Shetty, A. S.; Kumar, R. Ravi; Kumarappa, S.; Antony, A. J.

2016-09-01

The rate of economic evolution is untenable unless we save or stops misusing the fossil fuels like coal, crude oil or fossil fuels. So we are in need of start count on the alternate or renewable energy sources. In this experimental analysis an attempt has been made to investigate the conversion of municipal plastic wastes like milk covers and water bottles are selected as feed stocks to get oil using pyrolysis method, the performance analysis on CRDI diesel engine and to assess emission characteristics like HC, CO, NOX and smoke by using blends of Diesel-Plastic liquid fuels. The plastic fuel is done with the pH test using pH meter after the purification process and brought to the normal by adding KOH and NaOH. Blends of 0 to 100% plastic liquid fuel-diesel mixture have been tested for performance and emission aspect as well. The experimental results shows the efficiently convert weight of municipal waste plastics into 65% of useful liquid hydrocarbon fuels without emitting much pollutants.

Second law of thermodynamics in volume diffusion hydrodynamics in multicomponent gas mixtures

NASA Astrophysics Data System (ADS)

Dadzie, S. Kokou

2012-10-01

We presented the thermodynamic structure of a new continuum flow model for multicomponent gas mixtures. The continuum model is based on a volume diffusion concept involving specific species. It is independent of the observer's reference frame and enables a straightforward tracking of a selected species within a mixture composed of a large number of constituents. A method to derive the second law and constitutive equations accompanying the model is presented. Using the configuration of a rotating fluid we illustrated an example of non-classical flow physics predicted by new contributions in the entropy and constitutive equations.

Pressure and volume changes of tracheal tube cuff following inflation with various inflating agents during nitrous oxide anesthesia.

PubMed

Bajaj, Pramila; Nanda, Rajan; Goyal, Pradeep KR

2004-10-01

The study was designed to investigate the changes in pressure and volume of a tracheal tube-cuff inflated with air, mixture of N2O + O2, saline and 4% lidocaine during nitrous oxide anesthesia. This study was conducted in 80 patients (33 male & 47 female). The pressure and volume of a tracheal tube cuff increased with air, decreased with mixture of N2O + O2 and almost remained the same with saline and 4% lidocaine. The complications were more in the air group.

Validation of ATR FT-IR to identify polymers of plastic marine debris, including those ingested by marine organisms.

PubMed

Jung, Melissa R; Horgen, F David; Orski, Sara V; Rodriguez C, Viviana; Beers, Kathryn L; Balazs, George H; Jones, T Todd; Work, Thierry M; Brignac, Kayla C; Royer, Sarah-Jeanne; Hyrenbach, K David; Jensen, Brenda A; Lynch, Jennifer M

2018-02-01

Polymer identification of plastic marine debris can help identify its sources, degradation, and fate. We optimized and validated a fast, simple, and accessible technique, attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR), to identify polymers contained in plastic ingested by sea turtles. Spectra of consumer good items with known resin identification codes #1-6 and several #7 plastics were compared to standard and raw manufactured polymers. High temperature size exclusion chromatography measurements confirmed ATR FT-IR could differentiate these polymers. High-density (HDPE) and low-density polyethylene (LDPE) discrimination is challenging but a clear step-by-step guide is provided that identified 78% of ingested PE samples. The optimal cleaning methods consisted of wiping ingested pieces with water or cutting. Of 828 ingested plastics pieces from 50 Pacific sea turtles, 96% were identified by ATR FT-IR as HDPE, LDPE, unknown PE, polypropylene (PP), PE and PP mixtures, polystyrene, polyvinyl chloride, and nylon. Published by Elsevier Ltd.

Study of the influence of ZnO addition on the properties of chitosan-banana starch bioplastics

NASA Astrophysics Data System (ADS)

Sapei, L.; Padmawijaya, K. S.; Sijayanti, O.; Wardhana, P. J.

2017-07-01

Plastics have been widely used in our daily life due to their relatively low cost and practical uses. However, plastics are hardly degraded and thus creating lots of environmental problems. Bioplastics have been developed in order to replace the conventional plastics since they are easily degraded and environmentally friendly. In this research, chitosan-banana starch bioplastics were made with the ratio of 70:30 in the presence of 30% glycerol as the plasticizer. ZnO with varying concentrations of 1, 3, and 5% were added into the biopolymer mixtures before casting in order to improve their mechanical properties. It turned out that 3% ZnO significantly increased the bioplastics tensile strength up to ~36MPa. Vice versa, elongation and swelling percentage were decreased as ZnO concentrations increased. Bioplastics prepared with 3% ZnO were degraded within relatively short time in 90 min. These chitosan-banana starch bioplastics reinforced by ZnO seems quite promising to substitute some commercial conventional plastics.

Excess molar volumes of mixtures of hexane + natural oils from 298.15 to 313.15 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gonzalez, C.; Resa, J.M.; Ruiz, A.

1997-03-01

Excess molar volume data for mixtures containing hexane with three edible oils: olive, corn, and pip of grape have been determined from density measurements at various temperatures between 298.15 and 313.15 K using a vibrating tube densimeter. Results have been correlated by the Redlich-Kister equation. Systems showed negative deviations from ideality in the whole composition range.

Large Volume, Behaviorally-relevant Illumination for Optogenetics in Non-human Primates.

PubMed

Acker, Leah C; Pino, Erica N; Boyden, Edward S; Desimone, Robert

2017-10-03

This protocol describes a large-volume illuminator, which was developed for optogenetic manipulations in the non-human primate brain. The illuminator is a modified plastic optical fiber with etched tip, such that the light emitting surface area is > 100x that of a conventional fiber. In addition to describing the construction of the large-volume illuminator, this protocol details the quality-control calibration used to ensure even light distribution. Further, this protocol describes techniques for inserting and removing the large volume illuminator. Both superficial and deep structures may be illuminated. This large volume illuminator does not need to be physically coupled to an electrode, and because the illuminator is made of plastic, not glass, it will simply bend in circumstances when traditional optical fibers would shatter. Because this illuminator delivers light over behaviorally-relevant tissue volumes (≈ 10 mm 3 ) with no greater penetration damage than a conventional optical fiber, it facilitates behavioral studies using optogenetics in non-human primates.

Recycling of plastic: accounting of greenhouse gases and global warming contributions.

PubMed

Astrup, Thomas; Fruergaard, Thilde; Christensen, Thomas H

2009-11-01

Major greenhouse gas (GHG) emissions related to plastic waste recycling were evaluated with respect to three management alternatives: recycling of clean, single-type plastic, recycling of mixed/contaminated plastic, and use of plastic waste as fuel in industrial processes. Source-separated plastic waste was received at a material recovery facility (MRF) and processed for granulation and subsequent downstream use. In the three alternatives, plastic was assumed to be substituting virgin plastic in new products, wood in low-strength products (outdoor furniture, fences, etc.), and coal or fuel oil in the case of energy utilization. GHG accounting was organized in terms of indirect upstream emissions (e.g. provision of energy, fuels, and materials), direct emissions at the MRF (e.g. fuel combustion), and indirect downstream emissions (e.g. avoided emissions from production of virgin plastic, wood, or coal/oil). Combined, upstream and direct emissions were estimated to be roughly between 5 and 600 kg CO(2)-eq. tonne( -1) of plastic waste depending on treatment at the MRF and CO(2) emissions from electricity production. Potential downstream savings arising from substitution of virgin plastic, wood, and energy fuels were estimated to be around 60- 1600 kg CO(2)-eq. tonne( -1) of plastic waste depending on substitution ratios and CO(2) emissions from electricity production. Based on the reviewed data, it was concluded that substitution of virgin plastic should be preferred. If this is not viable due to a mixture of different plastic types and/or contamination, the plastic should be used for energy utilization. Recycling of plastic waste for substitution of other materials such as wood provided no savings with respect to global warming.

Concrete pavement mixture design and analysis (MDA) : effect of aggregate systems on concrete mixture properties.

DOT National Transportation Integrated Search

2012-07-01

For years, specifications have focused on the water to cement ratio (w/cm) and strength of concrete, despite the majority of the volume : of a concrete mixture consisting of aggregate. An aggregate distribution of roughly 60% coarse aggregate and 40%...

A critical test of bivelocity hydrodynamics for mixtures.

PubMed

Brenner, Howard

2010-10-21

The present paper provides direct noncircumstantial evidence in support of the existence of a diffuse flux of volume j(v) in mixtures. As such, it supersedes an earlier paper [H. Brenner, J. Chem. Phys. 132, 054106 (2010)], which offered only indirect circumstantial evidence in this regard. Given the relationship of the diffuse volume flux to the fluid's volume velocity, this finding adds additional credibility to the theory of bivelocity hydrodynamics for both gaseous and liquid continua, wherein the term bivelocity refers to the independence of the fluid's respective mass and volume velocities. Explicitly, the present work provides a new and unexpected linkage between a pair of diffuse fluxes entering into bivelocity mixture theory, fluxes that were previously regarded as constitutively independent, except possibly for their coupling arising as a consequence of Onsager reciprocity. In particular, for the case of a binary mixture undergoing an isobaric, isothermal, external force-free, molecular diffusion process we establish by purely macroscopic arguments-while subsequently confirming by purely molecular arguments-the validity of the ansatz j(v)=(v(1)-v(2))j(1) relating the diffuse volume flux j(v) to the diffuse mass fluxes j(1)(=-j(2)) of the two species and, jointly, their partial specific volumes v(1),v(2). Confirmation of that relation is based upon the use of linear irreversible thermodynamic principles to embed this ansatz in a broader context, and to subsequently establish the accord thereof with Shchavaliev's solution of the multicomponent Boltzmann equation for dilute gases [M. Sh. Shchavaliev, Fluid Dyn. 9, 96 (1974)]. Moreover, because the terms v(1), v(2), and j(1) appearing on the right-hand side of the ansatz are all conventional continuum fluid-mechanical terms (with j(1) given, for example, by Fick's law for thermodynamically ideal solutions), parity requires that j(v) appearing on the left-hand side of that relation also be a continuum term. Previously, diffuse volume fluxes, whether in mixtures or single-component fluids, were widely believed to be noncontinuum in nature, and hence of interest only to those primarily concerned with transport phenomena in rarefied gases. This demonstration of the continuum nature of bivelocity hydrodynamics suggests that the latter subject should be of general interest to all fluid mechanicians, even those with no special interest in mixtures.

Compatibility Assessment of Fuel System Infrastructure Plastics with Bio-oil and Diesel Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kass, Michael D.; Janke, Christopher James; Connatser, Raynella M.

We report that bio-oil derived via fast pyrolysis is being developed as a renewable fuel option for petroleum distillates. The compatibility of neat bio-oil with 18 plastic types was evaluated using neat diesel fuel as the baseline. The plastic materials included polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyoxymethylene (POM), POM copolymer, high density polyethylene (HDPE), polybutylene terephthalate (PBT), polypropylene (PP), polyethylene terephthalate glycol (PETG), polythiourea (PTU), four nylon grades, and four thermosetting resins. Specimens of each material were immersed in the test fuels for a period of 16 weeks to achieve full saturation. Except formore » PP and HDPE, the plastic materials underwent higher volume expansion in bio-oil than in the baseline diesel (which was negligible in most cases). This volume increase corresponds to the higher polarity of the bio-oil. PPS, PET, and PTFE were unaffected by bio-oil exposure, but modest swelling (between 2 and 5%) occurred for the two acetals (POM and POM copolymer), Nylon-12, PBT, PETG, and the four resin grades. More moderate swelling (8–15%) was noted for Nylon-6, Nylon-6/6, and Nylon-11, and excessive swell (>40%) occurred for PTU. The nonpolar nature of PP and HDPE matches that of diesel, leading to higher solubility (swell) in this fuel type. Finally, the relatively low volume expansion following exposure indicates that many of the existing infrastructure plastics (excluding PTU) should be suitable for use with bio-oil.« less

Transgenerational Actions of Environmental Compounds on Reproductive Disease and Identification of Epigenetic Biomarkers of Ancestral Exposures

PubMed Central

Tracey, Rebecca; Haque, Md. M.; Skinner, Michael K.

2012-01-01

Environmental factors during fetal development can induce a permanent epigenetic change in the germ line (sperm) that then transmits epigenetic transgenerational inheritance of adult-onset disease in the absence of any subsequent exposure. The epigenetic transgenerational actions of various environmental compounds and relevant mixtures were investigated with the use of a pesticide mixture (permethrin and insect repellant DEET), a plastic mixture (bisphenol A and phthalates), dioxin (TCDD) and a hydrocarbon mixture (jet fuel, JP8). After transient exposure of F0 gestating female rats during the period of embryonic gonadal sex determination, the subsequent F1–F3 generations were obtained in the absence of any environmental exposure. The effects on the F1, F2 and F3 generations pubertal onset and gonadal function were assessed. The plastics, dioxin and jet fuel were found to promote early-onset female puberty transgenerationally (F3 generation). Spermatogenic cell apoptosis was affected transgenerationally. Ovarian primordial follicle pool size was significantly decreased with all treatments transgenerationally. Differential DNA methylation of the F3 generation sperm promoter epigenome was examined. Differential DNA methylation regions (DMR) were identified in the sperm of all exposure lineage males and found to be consistent within a specific exposure lineage, but different between the exposures. Several genomic features of the DMR, such as low density CpG content, were identified. Exposure-specific epigenetic biomarkers were identified that may allow for the assessment of ancestral environmental exposures associated with adult onset disease. PMID:22389676

Naratriptan hydrochloride in extemporaneosly compounded oral suspensions.

PubMed

Zhang, Y P; Trissel, L A; Fox, J L

2000-01-01

The purpose of this study was to determine the pharmaceutical acceptability and chemical stability of naratriptan hydrochloride in three extemporaneously compounded suspension formulations. The naratriptan-hydrochloride oral suspensions were prepared from 2.5-mg commercial tablets yielding a nominal naratriptan concentration of 0.5 mg/mL. The suspension vehicles selected for testing were Syrpalta, an equal-parts mixture of Ora-Plus and Ora-Sweet, and an equal-parts mixture of Ora-Plus and Ora-Sweet SF. The tablets were crushed and thoroughly triturated to a fine powder using a porcelain mortar and pestle. The powder was incorporated into a portion of the Syrpalta or Ora-Plus suspension vehicle and mixed until homogeneous. The mixtures were then brought to volume with Syrpalta, Ora-Sweet or Ora-Sweet SF, as appropriate. The suspensions were packaged in amber, plastic, screw-cap prescription bottles and stored at 23 deg C for seven days and 4 deg C for 90 days. An adequate suspension was never achieved in Syrpalta. The crushed-tablet powder did not produce a uniformly dispersed mixture and exhibited clumping and a high rate of sedimentation. A distinct layer of the solid tablet material settled immediately after shaking. Over the next four hours, a densely packed, yellow, caked layer formed at the bottom of the containers, making resuspension difficult. During storage, the caking became worse. Chemical analysis was not performed. The Ora-Plus and Ora-Sweet or Ora-Sweet SF suspensions had a slight greenish cast and were resuspended without difficulty by shaking for approximately ten seconds, yielding easily poured and homogeneous mixtures throughout the study. Visible settling and layering did not begin for four hours with the Ora-Sweet suspension and 24 hours for the Ora-Sweet SF suspension. High pressure liquid chromatographic analysis found that the naratriptan concentration in both suspension-vehicle combinations exhibited little or no loss for seven days at 23 deg C and 90 days at 4 deg C. At least 96% of the inital concentration remained at all time points. Naratriptan hydrochloride extemporaneously prepared as oral suspensions from tablets in equal-parts mixtures of Ora-Plus suspension vehicle with Ora-Sweet and with Ora-Sweet SF syrups was pharmaceutically acceptable and chemically stable for at least seven days at 23 deg C and 90 days at 4 deg C. Syrpalta was unacceptable for use as a vehicle for naratriptan hydrochloride suspensions prepared from tablets.

Effects of sex and seasonality on the song control system and FoxP2 protein expression in black-capped chickadees (Poecile atricapillus).

PubMed

Phillmore, Leslie S; MacGillivray, Heather L; Wilson, K Ryan; Martin, Stephanie

2015-02-01

Plasticity in behavior is mirrored by corresponding plasticity in the brain in many songbird species. In some species, song system nuclei (Phillmore et al. [2006]: J Neurobiol 66:1002-1010) are larger in birds in breeding condition than birds in nonbreeding condition, possibly due to increased vocal output in spring. FOXP2, a transcription factor associated with language expression and comprehension in humans and song learning in songbirds, also shows plasticity. FoxP2 expression in songbird Area X, a region important for sensorimotor integration, is related to developmental and adult vocal plasticity (Teramitsu et al. [2010]: J Neurosci 24:3152-3163, Chen et al. [2013], J Exp Biol 216:3682-3692). In this study, we examined whether sex and breeding condition affects both song control system volume (HVC, X) and FoxP2 protein expression in black-capped chickadees (Poecile atricapillus). HVC volume was larger in males in breeding condition than males in nonbreeding condition, but there were no sex differences. In contrast, Area X volume was larger in males than females, regardless of breeding condition, likely reflecting that male and female chickadees produce learned chick-a-dee calls year round, but output of the learned song increases in breeding males. FoxP2 protein levels did not differ between sexes or breeding condition when calculated as a ratio of labeled cells in Area X to labeled cells in the surrounding striato-pallium, however, absolute density of FoxP2 in both regions was higher in males than in females. This may indicate that chickadees maintain a level of FoxP2 necessary for plasticity year-round, but males have greater potential for plasticity compared to females. © 2014 Wiley Periodicals, Inc.

Proper Accounting for Surface Area to Solution Volume Ratios in Exaggerated Extractions.

PubMed

Jenke, Dennis R; Rabinow, Barrett E

2017-01-01

When drug products contact plastic manufacturing components, packaging systems, and/or delivery devices, leachables from the plastics can accumulate in the drug product, potentially affecting its key quality attributes. Given practical issues associated with screening drug products for leachables, potential leachables are frequently surfaced as extractables revealed in extraction studies. To facilitate extractables discovery and identification and to shorten extraction times, extraction studies can be exaggerated and/or accelerated. One means of exaggerating an extraction is to increase the test article's extracted surface area to extraction solution volume ratio (SA/V), as it is generally accepted that an extractable's concentration in an extract is proportional to SA/V in a 1 to 1 manner. However, as the relationship between an extractable's concentration and SA/V depends on the extractable's plastic/solvent partition coefficient (k p/l ), the effect of SA/V on the extractable's concentrations can be either under- or over-estimated if a 1 to 1 proportion is used. This article presents the theoretical relationship between SA/V, concentration, and k p/l ; illustrates theory with a case study; and suggests proper exaggeration strategies. LAY ABSTRACT: When drug products are manufactured, stored, or delivered in systems that contain plastics, substances can be leached from the plastics and remain in the drug product, where they might affect the product's key quality attributes. To discover and identify these leached substances, the plastics are extracted under laboratory conditions and the extracts are appropriately tested. To facilitate this process, extracts may be generated under laboratory conditions that exaggerate or accelerate the drug product's clinical conditions of manufacturing or use. The proper use of the ratio of the extracted item's surface area to the volume of the extracting solution as an exaggeration parameter is discussed in this paper. © PDA, Inc. 2017.

Stress Wave Propagation in Viscoelastic-Plastic Rock-Like Materials.

PubMed

Lang, Liu; Song, Ki-Il; Zhai, Yue; Lao, Dezheng; Lee, Hang-Lo

2016-05-17

Rock-like materials are composites that can be regarded as a mixture composed of elastic, plastic, and viscous components. They exhibit viscoelastic-plastic behavior under a high-strain-rate loading according to element model theory. This paper presents an analytical solution for stress wave propagation in viscoelastic-plastic rock-like materials under a high-strain-rate loading and verifies the solution through an experimental test. A constitutive equation of viscoelastic-plastic rock-like materials was first established, and then kinematic and kinetic equations were then solved to derive the analytic solution for stress wave propagation in viscoelastic-plastic rock-like materials. An experimental test using the SHPB (Split Hopkinson Pressure Bar) for a concrete specimen was conducted to obtain a stress-strain curve under a high-strain-rate loading. Inverse analysis based on differential evolution was conducted to estimate undetermined variables for constitutive equations. Finally, the relationship between the attenuation factor and the strain rate in viscoelastic-plastic rock-like materials was investigated. According to the results, the frequency of the stress wave, viscosity coefficient, modulus of elasticity, and density play dominant roles in the attenuation of the stress wave. The attenuation decreases with increasing strain rate, demonstrating strongly strain-dependent attenuation in viscoelastic-plastic rock-like materials.

Stress Wave Propagation in Viscoelastic-Plastic Rock-Like Materials

PubMed Central

Lang, Liu; Song, KI-IL; Zhai, Yue; Lao, Dezheng; Lee, Hang-Lo

2016-01-01

Rock-like materials are composites that can be regarded as a mixture composed of elastic, plastic, and viscous components. They exhibit viscoelastic-plastic behavior under a high-strain-rate loading according to element model theory. This paper presents an analytical solution for stress wave propagation in viscoelastic-plastic rock-like materials under a high-strain-rate loading and verifies the solution through an experimental test. A constitutive equation of viscoelastic-plastic rock-like materials was first established, and then kinematic and kinetic equations were then solved to derive the analytic solution for stress wave propagation in viscoelastic-plastic rock-like materials. An experimental test using the SHPB (Split Hopkinson Pressure Bar) for a concrete specimen was conducted to obtain a stress-strain curve under a high-strain-rate loading. Inverse analysis based on differential evolution was conducted to estimate undetermined variables for constitutive equations. Finally, the relationship between the attenuation factor and the strain rate in viscoelastic-plastic rock-like materials was investigated. According to the results, the frequency of the stress wave, viscosity coefficient, modulus of elasticity, and density play dominant roles in the attenuation of the stress wave. The attenuation decreases with increasing strain rate, demonstrating strongly strain-dependent attenuation in viscoelastic-plastic rock-like materials. PMID:28773500

Synthesis of biodegradable plastic from tapioca with N-Isopropylacrylamid and chitosan using glycerol as plasticizer

NASA Astrophysics Data System (ADS)

Syaubari; Safwani, S.; Riza, M.

2018-04-01

One of natural polymers that can be used as raw material in the manufacture of biodegradable plastic is tapioca and chitosan. The addition of other compounds such as glycerol as plasticizer is to improve the characteristics of the plastic that already produced. N- Isopropylacrylamid (NIPAm) is an organic compound that can be synthesized into a polymer or polymer grafting which also biodegradable too. This research aims tostudy the synthesis of biodegradable plastics from tapioca with the addition of chitosan, NIPAm, poly(NIPAm) and analyze the characteristics of biodegradable plastics that already produced. This research was done in three stages, there are (1) polymerization NIPAm, (2) the grafting of chitosan-poly NIPAm and (3) the synthesis of biodegradable plastics from starch mixture with variation of addition chitosan, NIPAm, poly(NIPAm), chitosan-graft-poly(NIPAm) and also variations of glycerol as plasticizer. The results of this research is a thin sheet of plastic which is will get analyzed for the characteristics of functional groups, mechanical, morphological and its biodegradability. FTIR spectra showed the grafting process with the new group formation of CO single-bond at 850 cm-1. Plastic with the addition of NIPAm and 1 ml glycerol has the highest tensile strength value about 31.1 MPa. Plastic with poly(NIPAm) and 4 ml glycerol produces the highest elongation value about 153.72%. Plastic with Chitosan-graft-poly(NIPAm) with 1 ml glycerol has the longest biodegradation because of the small mass-loss for six weeks which is about 6.6%.

Investigation of Nonlinear Site Response and Seismic Compression from Case History Analysis and Laboratory Testing

NASA Astrophysics Data System (ADS)

Yee, Eric

In this thesis I address a series of issues related to ground failure and ground motions during earthquakes. A major component is the evaluation of cyclic volumetric strain behavior of unsaturated soils, more commonly known as seismic compression, from advanced laboratory testing. Another major component is the application of nonlinear and equivalent linear ground response analyses to large-strain problems involving highly nonlinear dynamic soil behavior. These two components are merged in the analysis of a truly unique and crucial field case history of nonlinear site response and seismic compression. My first topic concerns dynamic soil testing for relatively small strain dynamic soil properties such as threshold strains, gammatv. Such testing is often conducted using specialized devices such as dual-specimen simple-shear, as devices configured for large strain testing produce noisy signals in the small strain range. Working with a simple shear device originally developed for large-strain testing, I extend its low-strain capabilities by characterizing noisy signals and utilizing several statistical methods to extract meaningful responses in the small strain range. I utilize linear regression of a transformed variable to estimate the cyclic shear strain from a noisy signal and the confidence interval on its amplitude. I utilize Kernel regression with the Nadaraya-Watson estimator and a Gaussian kernel to evaluate vertical strain response. A practical utilization of these techniques is illustrated by evaluating threshold shear strains for volume change with a procedure that takes into account uncertainties in the measured shear and vertical strains. My second topic concerns the seismic compression characteristics of non-plastic and low-plasticity silty sands with varying fines content (10 ≤ FC ≤ 60%). Simple shear testing was performed on various sand-fines mixtures at a range of modified Proctor relative compaction levels ( RC) and degrees-of-saturation (S). Aside from the expected strong influence of RC, increasing fines content is found to generally decrease volume change for fines fractions consisting of silts and clayey silts with moderate to low plasticity. With truly non-plastic fines (rock flour), cyclic volume change increases with FC. Some materials also exhibit an effect of as-compacted saturation in which moderate saturation levels associated with high matric suction cause volume change to decrease. A preliminary empirical model to capture these effects is presented. The balance of the dissertation is related to a case history of strongly nonlinear site response and seismic compression associated with a free-field downhole array installed near the Service Hall at the Kashiwazaki-Kariwa nuclear power plant, which recorded strong ground motions from the Mw 6.6 2007 Niigata-ken Chuetsu-oki earthquake. Site conditions at the array consist of about 70 m of medium-dense sands overlying clayey bedrock, with ground water located at 45 m. Ground shaking at the bedrock level had geometric mean peak accelerations of 0.55 g which is reduced to 0.4 g at the ground surface, indicating nonlinear site response. Ground settlements of approximately 15+/-5 cm occurred at the site. A site investigation was performed to develop relevant soil properties for ground response and seismic compression analysis, including shear wave velocities, shear strength, relative density, and modulus reduction and damping curves. (Abstract shortened by UMI.)

The Influence of Injection Molding Parameter on Properties of Thermally Conductive Plastic

NASA Astrophysics Data System (ADS)

Hafizah Azis, N.; Zulafif Rahim, M.; Sa'ude, Nasuha; Rafai, N.; Yusof, M. S.; Tobi, ALM; Sharif, ZM; Rasidi Ibrahim, M.; Ismail, A. E.

2017-05-01

Thermally conductive plastic is the composite between metal-plastic material that is becoming popular because if it special characteristic. Injection moulding was regarded as the best process for mass manufacturing of the plastic composite due to its low production cost. The objective of this research is to find the best combination of the injection parameter setting and to find the most significant factor that effect the strength and thermal conductivity of the composite. Several parameter such as the volume percentage of copper powder, nozzle temperature and injection pressure of injection moulding machine were investigated. The analysis was done using Design Expert Software by implementing design of experiment method. From the analysis, the significant effects were determined and mathematical models of only significant effect were established. In order to ensure the validity of the model, confirmation run was done and percentage errors were calculated. It was found that the best combination parameter setting to maximize the value of tensile strength is volume percentage of copper powder of 3.00%, the nozzle temperature of 195°C and the injection pressure of 65%, and the best combination parameter settings to maximize the value of thermal conductivity is volume percentage of copper powder of 7.00%, the nozzle temperature of 195°C and the injection pressure of 65% as recommended..

Low volume tubes are not effective to reduce the rate of hemolyzed specimens from the emergency department.

PubMed

Lippi, Giuseppe; Bonelli, Patrizia; Graiani, Virna; Caleffi, Catia; Cervellin, Gianfranco

2014-02-01

Spurious hemolysis is the leading source of nonconformities that can be recorded in diagnostic samples, especially those collected in the emergency department (ED). The aim of this study was to assess whether the shift from regular to low volume blood collection tubes may reduce the rate of hemolysis in a large urban ED, where approximately 80% of blood collections are performed through catheters. In a former 5-month period, blood collection in the ED was performed using 5.0mL (13×100mm) plastic serum tubes, which were then completely replaced with 3.5mL (13×75mm) plastic serum tubes for another period of 5months. The rate of hemolyzed specimens (i.e., those containing a cell-free hemoglobin ≥0.5gL) collected in the two periods was compared by Fisher exact test. The rate of hemolyzed specimens received from the ED increased from 3.5% using 5.0mL plastic serum tubes to 5.2% after introduction of 3.5mL plastic serum tubes (p<0.001). The use of low volume tubes was not effective to decrease the hemolysis rate in a large urban ED. Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Experience-dependent mushroom body plasticity in butterflies: consequences of search complexity and host range

PubMed Central

Janz, Niklas; Schäpers, Alexander; Gamberale-Stille, Gabriella

2017-01-01

An ovipositing insect experiences many sensory challenges during her search for a suitable host plant. These sensory challenges become exceedingly pronounced when host range increases, as larger varieties of sensory inputs have to be perceived and processed in the brain. Neural capacities can be exceeded upon information overload, inflicting costs on oviposition accuracy. One presumed generalist strategy to diminish information overload is the acquisition of a focused search during its lifetime based on experiences within the current environment, a strategy opposed to a more genetically determined focus expected to be seen in relative specialists. We hypothesized that a broader host range is positively correlated with mushroom body (MB) plasticity, a brain structure related to learning and memory. To test this hypothesis, butterflies with diverging host ranges (Polygonia c-album, Aglais io and Aglais urticae) were subjected to differential environmental complexities for oviposition, after which ontogenetic MB calyx volume differences were compared among species. We found that the relative generalist species exhibited remarkable plasticity in ontogenetic MB volumes; MB growth was differentially stimulated based on the complexity of the experienced environment. For relative specialists, MB volume was more canalized. All in all, this study strongly suggests an impact of host range on brain plasticity in Nymphalid butterflies. PMID:29093221

Surface treatment with Fenton for separation of acrylonitrile-butadiene-styrene and polyvinylchloride waste plastics by flotation.

PubMed

Wang, Jian-Chao; Wang, Hui; Huang, Luo-Luo; Wang, Chong-Qing

2017-09-01

Surface treatment with Fenton was applied to flotation separation of acrylonitrile-butadienestyrene (ABS) and polyvinylchloride (PVC). After treatment, the floatability of ABS has a dramatic decrease, while the floatability of PVC is not affected. Fourier transform infrared spectroscopy (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) spectra were recorded to ascertain the mechanism of Fenton treatment. FT-IR and XPS analysis confirms that the introduction of oxygen-containing group occurs on the surface of ABS. The optimum conditions are molar ration (H 2 O 2 :Fe 2+ ) 10000, H 2 O 2 concentration 0.4M/L, pH 5.8, treatment time 2min and temperature 25°C, frother concentration 15mg/L and flotation time 3min. Particle sizes and mixing ratios were also investigated. Plastic mixtures of ABS and PVC with different particle sizes and mixing ratios can be effectively separated. The purity of ABS and PVC are up to 100% and 99.78%, respectively; the recovery of ABS and PVC are up to 99.89% and 100%, respectively. A practical, environmentally friendly and effective reagent, namely Fenton, was originally applied to surface treatment of ABS and PVC waste plastics for flotation separation of their mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

46 CFR 162.050-3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-water mixture to provide a resulting mixture that has an oil concentration of 15 ppm or less. Bilge... content meters, or bilge alarms. Oil content meter or meter means a component of the oil discharge... and oily mixtures combined with these residues. PPM means parts per million by volume of oil in water...

Viscosity and density of methanol/water mixtures at low temperatures

NASA Technical Reports Server (NTRS)

Austin, J. G.; Kurata, F.; Swift, G. W.

1968-01-01

Viscosity and density are measured at low temperatures for three methanol/water mixtures. Viscosity is determined by a modified falling cylinder method or a calibrated viscometer. Density is determined by the volume of each mixture contained in a calibrated glass cell placed in a constant-temperature bath.

Perilous plastics - are phthalate esters a risk for human reproductive health?

EPA Science Inventory

Phthalate diesters are high-production volume chemicals used to impart flexibility to polyvinyl chloride plastic (e.g. children’s toys and medical tubing) and are also found in other products (e.g. health and beauty products). Certain phthalate esters inhibit reproductive develop...

Perilous plasticizers - are phthalate esters a risk for human reproductive health?

EPA Science Inventory

Phthalate diesters are high-production volume chemicals used to impart flexibility to polyvinyl chloride plastic (e.g. children’s toys and medical tubing) as well as other products (e.g. health and beauty products). Certain phthalate esters inhibit reproductive development in la...

Separation properties of aluminium-plastic laminates in post-consumer Tetra Pak with mixed organic solvent.

PubMed

Zhang, S F; Zhang, L L; Luo, K; Sun, Z X; Mei, X X

2014-04-01

The separation properties of the aluminium-plastic laminates in postconsumer Tetra Pak structure were studied in this present work. The organic solvent blend of benzene-ethyl alcohol-water was used as the separation reagent. Then triangle coordinate figure analysis was taken to optimize the volume proportion of various components in the separating agent and separation process. And the separation temperature of aluminium-plastic laminates was determined by the separation time, efficiency, and total mass loss of products. The results show that cost-efficient separations perform best with low usage of solvents at certain temperatures, for certain times, and within a certain range of volume proportions of the three components in the solvent agent. It is also found that similar solubility parameters of solvents and polyethylene adhesives (range 26.06-34.85) are a key factor for the separation of the aluminium-plastic laminates. Such multisolvent processes based on the combined-system concept will be vital to applications in the recycling industry.

Facile characterization of polymer fractions from waste electrical and electronic equipment (WEEE) for mechanical recycling.

PubMed

Taurino, Rosa; Pozzi, Paolo; Zanasi, Tania

2010-12-01

In view of the environmental problem involved in the management of WEEE, and then in the recycling of post-consumer plastic of WEEE there is a pressing need for rapid measurement technologies for simple identification of the various commercial plastic materials and of the several contaminants, to improve the recycling of such wastes. This research is focused on the characterization and recycling of two types of plastics, namely plastic from personal computer (grey plastic) and plastic from television (black plastic). Various analytical techniques were used to monitor the compositions of WEEE. Initially, the chemical structure of each plastic material was identified by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). Polymeric contaminants of these plastics, in particular brominated flame retardants (BFRs) were detected in grey plastics only using different techniques. These techniques are useful for a rapid, correct and economics identification of a large volumes of WEEE plastics. Copyright © 2010 Elsevier Ltd. All rights reserved.

Public Interest in Breast Augmentation: Analysis and Implications of Google Trends Data.

PubMed

Wilson, Stelios C; Daar, David A; Sinno, Sammy; Levine, Steven M

2018-06-01

Breast augmentation is the most common aesthetic surgery performed in the United States (US) annually. Analysis of Google Trends (GT) data may give plastic surgeons useful information regarding worldwide, national, and regional interest for breast augmentation and other commonly performed aesthetic surgeries. Data were collected using GT for breast augmentation and associated search terms from January 2004 to May 2017. Case volume was obtained from the American Society of Plastic Surgeons (ASPS) annual reports for the calendar year 2005-2016. Trend analysis showed that total search term volume for breast augmentation and breast implants gradually decreased worldwide and in the US over the study period while the search term boob job slowly increased. Univariate linear regression demonstrated a statistically significant positive correlation between average annual Google search volume of "breast augmentation" and the annual volume of breast augmentations performed in the US according to ASPS data (R 2  = 0.44, p = 0.018). There was no significant correlation between national volume of breast augmentations performed and search volume using the terms "breast implants" or "boob job" over time (p = 0.84 and p = 0.07, respectively). In addition, there appears to be country specific variation in interest based on time of year and peaks in interest following specific policies. To our knowledge, this is the first and only analysis of GT data in the plastic surgery literature to date. To that end, this study highlights this large and potentially powerful data set for plastic surgeons both in the US and around the world. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Results of herbicide trials to control Japanese honeysuckle

Treesearch

Silas Little; Horace A. Somes

1967-01-01

Three or more annual sprays are required to eliminate Japanese honeysuckle where 2,4-D, a mixture of 2,4-D and 2,4,5-T, or amitrole is applied as either a low-volume (mistblower) or high-volume spray. Dicamba and picloram are more effective. The mixture of 2,4-D and picloram is recommended as the best material for eliminating honeysuckle in a single treatment at the...

A Review and Evaluation of the Phase Equilibria, Liquid-Phase Heats of Mixing and Excess Volumes, and Gas-Phase PVT Measurements for Nitrogen+Methane

NASA Astrophysics Data System (ADS)

Kidnay, A. J.; Miller, R. C.; Sloan, E. D.; Hiza, M. J.

1985-07-01

The available experimental data for vapor-liquid equilibria, heat of mixing, change in volume on mixing for liquid mixtures, and gas-phase PVT measurements for nitrogen+methane have been reviewed and where possible evaluated for consistency. The derived properties chosen for analysis and correlation were liquid mixture excess Gibbs free energies, and Henry's constants.

Applications and societal benefits of plastics

PubMed Central

Andrady, Anthony L.; Neal, Mike A.

2009-01-01

This article explains the history, from 1600 BC to 2008, of materials that are today termed ‘plastics’. It includes production volumes and current consumption patterns of five main commodity plastics: polypropylene, polyethylene, polyvinyl chloride, polystyrene and polyethylene terephthalate. The use of additives to modify the properties of these plastics and any associated safety, in use, issues for the resulting polymeric materials are described. A comparison is made with the thermal and barrier properties of other materials to demonstrate the versatility of plastics. Societal benefits for health, safety, energy saving and material conservation are described, and the particular advantages of plastics in society are outlined. Concerns relating to littering and trends in recycling of plastics are also described. Finally, we give predictions for some of the potential applications of plastic over the next 20 years. PMID:19528050

Art and Plastic Surgery.

PubMed

Fernandes, Julio Wilson; Metka, Susanne

2016-04-01

The roots of science and art of plastic surgery are very antique. Anatomy, drawing, painting, and sculpting have been very important to the surgery and medicine development over the centuries. Artistic skills besides shape, volume, and lines perception can be a practical aid to the plastic surgeons' daily work. An overview about the interactions between art and plastic surgery is presented, with a few applications to rhinoplasty, cleft lip, and other reconstructive plastic surgeries. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Potential low cost, safe, high efficiency propellant for future space program

NASA Astrophysics Data System (ADS)

Zhou, D.

2005-03-01

Mixtures of nanometer or micrometer sized carbon powder suspended in hydrogen and methane/hydrogen mixtures are proposed as candidates for low cost, high efficiency propellants for future space programs. While liquid hydrogen has low weight and high heat of combustion per unit mass, because of the low mass density the heat of combustion per unit volume is low, and the liquid hydrogen storage container must be large. The proposed propellants can produce higher gross heat combustion with small volume with trade off of some weight increase. Liquid hydrogen can serve as the fluid component of the propellant in the mixtures and thus used by current rocket engine designs. For example, for the same volume a mixture of 5% methane and 95% hydrogen, can lead to an increase in the gross heat of combustion by about 10% and an increase in the Isp (specific impulse) by 21% compared to a pure liquid hydrogen propellant. At liquid hydrogen temperatures of 20.3 K, methane will be in solid state, and must be formed as fine granules (or slush) to satisfy the requirement of liquid propellant engines.

Carbon deposition model for oxygen-hydrocarbon combustion, volume 1

NASA Technical Reports Server (NTRS)

Hernandez, R.; Ito, J. I.; Niiya, K. Y.

1987-01-01

Presented are details of the design, fabrication, and testing of subscale hardware used in the evaluation of carbon deposition characteristics of liquid oxygen and three hydrocarbon fuels for both main chamber and preburner/gas generator operating conditions. In main chamber conditions, the deposition of carbon on the combustion chamber wall was investigated at mixture ratios of 2.0 to 4.0 and at pressures of 1000 to 1500 psia. No carbon deposition on the chamber walls was detected at these main chamber mixture ratios. In preburner/gas generator operating conditions, the deposition of carbon on the turbine simulator tubes was evaluated at mixture ratios of 0.20 to 0.60 and at chamber pressures of 720 to 1650 psia. The results of the tests showed carbon deposition rate to be a strong function of mixture ratio and a weak function of chamber pressure. Further analyses evaluated the operational consequences of carbon deposition on preburner/gas generator performance. The report is in two volumes, of which this is Volume 1 covering the main body of the report plus Appendixes A through D.

Localization of ductile deformation in lithosphere and rocks: the role of grain boundary sliding

NASA Astrophysics Data System (ADS)

Dimanov, Alexandre; Rahanel, Jean; Bornert, Michel; Bourcier, Mathieu; Gaye, Ag; Heripre, Eva; Ludwig, Wolfgang

2017-04-01

Ductile strain of the lithosphere localizes in multi-scale shear zones, ranging from km to mm scales. The resulting mylonites/ultramylonites present microstructural signatures of several concomitant deformation mechanisms. Besides cataclastic features, crystal plasticity dominates in volume, but grain boundary sliding and diffusive/solution mass transport act along interfaces. Considering solely the inherited natural microstructures does not make clear the chronology of appearance and the interactions between these mechanisms. Therefore, inference of the overall mylonitic rheology seems illusory. We have therefore realized over the last decade a systematic rheological characterization of the high temperature flow of various synthetic anorthite - diopside mixtures. The data clearly suggest Newtonian type of rheology as best adapted to the materials representative of the lower crust mylonites. However, the post mortem microstructures undoubtedly evidenced the coexistence of both crystal plasticity and grain boundary sliding processes. Yet, the specific roles of each mechanism in the localization process remained unclear. In order to clarify these aspects we realized a multi-scale micromechanical in situ investigation of the ductile deformation of synthetic rock-salt. The mechanical tests were combined with in-situ optical microscopy, scanning electron microscopy and X-ray tomography (MCT). Digital image correlation (DIC) techniques allowed for measurements and characterization of the multi-scale organization of 2D and 3D full strain fields. Macroscopic and mesoscopic shear bands appear at the sample and microstructure scales, respectively. DIC evidenced the development of discrete slip bands within individual grains, and hence of dominant crystal plasticity. Combination of DIC and EBSD allowed for identification of active slip systems. Conversely, DIC allowed for the identification and the precise quantification of minor activity (< 5% contribution) of grain boundary sliding (GBS). Most importantly, GBS is continuously operating along with crystal slip plasticity, which indicates that in spite of being a secondary mechanism it is a necessary one. GBS seems to accommodate very efficiently for plastic strain incompatibilities between neighboring grains. Our finding is strengthened by finite element (FE) modeling of the viscoplastic behavior of rock-salt, which appears inadequate in detail if solely based on crystal plasticity. Moreover, the local GBS appears to i) trigger the formation of localized shear bands at the microstructure scale, and ii) allow for homogenization of ductile strain throughout the whole specimen. Our major conclusions are that crystal plasticity and GBS are not really dissociable. They are co-operative mechanisms that accommodate each other depending on microstructure and loading conditions. Minor GBS is always necessary in order to accommodate for the pronounced plastic anisotropy of minerals. Conversely, localized minor crystal plasticity is necessary to accommodate dominant GBS. Finally, GBS is directly involved in the initial development of localized ductile strain at the aggregate scale. But, GBS might take over as the dominant mechanism within fine grained mylonites and contribute to the large scale shear zone localization.

Degradation of PVC/rPLA Thick Films in Soil Burial Experiment

NASA Astrophysics Data System (ADS)

Nowak, Bożena; Rusinowski, Szymon; Chmielnicki, Blazej; Kamińska-Bach, Grażyna; Bortel, Krzysztof

2016-10-01

Some of the biodegradable polymers can be blended with a synthetic polymer to facilitate their biodegradation in the environment. The objective of the study was to investigate the biodegradation of thick films of poly(vinyl chloride)/recycled polylactide (PVC/rPLA). The experiments were carried out in the garden soil or in the mixture of garden soil and hydrocarbon-contaminated soil under laboratory conditions. Since it is widely accepted that the biosurfactants secreted by microorganisms enable biotransformation of various hydrophobic substances in the environment, it was assumed that the use of contaminated soil, rich in biosurfactant producing bacteria, may accelerate biodegradation of plastics. After the experimental period, the more noticeable weight loss of polymer films was observed after incubation in the garden soil. However, more pronounced changes in the film surface morphology and chemical structure as well as decrease of tensile strength were observed after incubation of films in the mixture of garden and contaminated soil. It turned out that as a result of competition between two distinct groups of microorganisms present in the mixture of garden and hydrocarbon-contaminated soils the number of microorganisms and their activity were lower than the activity of indigenous microflora of garden soil as well as the amount of secreted biosurfactants towards plastics.

Taste Masking of Griseofulvin and Caffeine Anhydrous Using Kleptose Linecaps DE17 by Hot Melt Extrusion.

PubMed

Juluri, Abhishek; Popescu, Carmen; Zhou, Leon; Murthy, Reena N; Gowda, Vanaja K; Chetan Kumar, P; Pimparade, Manjeet B; Repka, Michael A; Murthy, S Narasimha

2016-02-01

The objective of this project was to investigate the potential of Kleptose Linecaps DE17 (KLD) in masking the unpleasant/bitter taste of therapeutic agents by hot melt extrusion (HME). Griseofulvin (GRI) and caffeine anhydrous (CA) were used as a bitter active pharmaceutical ingredient (API) model drugs. Thermogravimetric studies confirmed the stability of GRI, CA, and KLD at the employed extrusion temperatures. The differential scanning calorimetry (DSC) studies revealed a characteristic melting endotherm of GRI at 218-220°C and CA at 230-232°C in the physical mixtures as well as in all extrudates over the period of study, indicating the crystalline nature of drug. HME of KLD was achieved only in the presence of plasticizer. Among the several plasticizers investigated, xylitol showed improved processability of KLD at 15% w/w concentration. Dissolution studies of HME extrudates using simulated salivary medium exhibited ∼threefold less release compared to physical mixture at the end of 5 min (the lesser drug release, better the taste masking efficiency). Furthermore, the results from the sensory evaluation of products in human panel demonstrated strong bitter taste in the case of physical mixture compared to the HME formulation, suggesting the potential of Kleptose Linecaps DE17 as taste masking polymer in melt extruded form.

Stability of extemporaneously prepared moxifloxacin oral suspensions.

PubMed

Hutchinson, David J; Johnson, Cary E; Klein, Kristin C

2009-04-01

The stability of extemporaneously prepared moxifloxacin oral suspensions was studied. An oral suspension of moxifloxacin 20 mg/mL was prepared by thoroughly grinding three 400-mg tablets of moxifloxacin in a glass mortar. Thirty milliliters of Ora-Plus and 30 mL of either Ora-Sweet or Ora-Sweet SF were mixed and added to the powder to make a final volume of 60 mL. Three identical samples of each formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and were stored at room temperature (23-25 degrees C). A 1-mL sample was withdrawn from each of the six bottles with a micropipette immediately after preparation and at 7, 14, 28, 60, and 90 days. After further dilution to an expected concentration of 8 microg/ mL with sample diluent, the samples were assayed in duplicate by stability-indicating high-performance liquid chromatography. Stability was defined as the retention of at least 90% of the initial concentration. At least 99% of the initial moxifloxacin remained throughout the 90-day study period in both preparations. There were no detectable changes in color, odor, taste, and pH and no visible microbial growth in any sample. Extemporaneously compounded suspensions of moxifloxacin 20 mg/mL in a 1:1 mixture of Ora-Plus and Ora-Sweet or Ora-Sweet SF were stable for at least 90 days when stored in 2-oz amber plastic bottles at room temperature.

Learning Modifies Odor Mixture Processing to Improve Detection of Relevant Components

PubMed Central

Chen, Jen-Yung; Marachlian, Emiliano; Assisi, Collins; Huerta, Ramon; Smith, Brian H.

2015-01-01

Honey bees have a rich repertoire of olfactory learning behaviors, and they therefore are an excellent model to study plasticity in olfactory circuits. Recent behavioral, physiological, and molecular evidence suggested that the antennal lobe, the first relay of the olfactory system in insects and analog to the olfactory bulb in vertebrates, is involved in associative and nonassociative olfactory learning. Here we use calcium imaging to reveal how responses across antennal lobe projection neurons change after association of an input odor with appetitive reinforcement. After appetitive conditioning to 1-hexanol, the representation of an odor mixture containing 1-hexanol becomes more similar to this odor and less similar to the background odor acetophenone. We then apply computational modeling to investigate how changes in synaptic connectivity can account for the observed plasticity. Our study suggests that experience-dependent modulation of inhibitory interactions in the antennal lobe aids perception of salient odor components mixed with behaviorally irrelevant background odors. PMID:25568113

Development of concrete shrinkage performance specifications.

DOT National Transportation Integrated Search

2003-01-01

During its service life, concrete undergoes volume changes. One of the types of deformation is shrinkage. The four main types of shrinkage associated with concrete are plastic, autogenous, carbonation, and drying shrinkage. The volume changes in conc...

Nutritional and sensory characteristics of gluten-free quinoa (Chenopodium quinoa Willd)-based cookies development using an experimental mixture design.

PubMed

Brito, Isabelle L; de Souza, Evandro Leite; Felex, Suênia Samara Santos; Madruga, Marta Suely; Yamashita, Fábio; Magnani, Marciane

2015-09-01

The aim of this study was to develop a gluten-free formulation of quinoa (Chenopodium quinoa Willd.)-based cookies using experimental design of mixture to optimize a ternary mixture of quinoa flour, quinoa flakes and corn starch for parameters of colour, specific volume and hardness. Nutritional and sensory aspects of the optimized formulation were also assessed. Corn starch had a positive effect on the lightness of the cookies, but increased amounts of quinoa flour and quinoa flakes in the mixture resulted in darker product. Quinoa flour showed a negative effect on the specific volume, producing less bulky cookies, and quinoa flour and quinoa flakes had a positive synergistic effect on the hardness of the cookies. According the results and considering the desirability profile for colour, hardness and specific volume in gluten-free cookies, the optimized formulation contains 30 % quinoa flour, 25 % quinoa flakes and 45 % corn starch. The quinoa-based cookie obtained was characterized as a product rich in dietary fibre, a good source of essential amino acids, linolenic acid and minerals, with good sensory acceptability. These findings reports for the first time the application of quinoa processed as flour and flakes in mixture with corn starch as an alternative ingredient for formulations of gluten-free cookies-type biscuits.

PROCESS OF MAKING SHAPED FUEL FOR NUCLEAR REACTORS

DOEpatents

O'Leary, W.J.; Fisher, E.A.

1964-02-11

A process for making uranium dioxide fuel of great strength, density, and thermal conductivity by mixing it with 0.1 to 1% of a densifier oxide (tin, aluminum, zirconium, ferric, zinc, chromium, molybdenum, titanium, or niobium oxide) and with a plasticizer (0.5 to 3% of bentonite and 0.05 to 2% of methylcellulose, propylene glycol alginate, or ammonium alginate), compacting the mixture obtained, and sintering the bodies in an atmosphere of carbon monoxide or carbon dioxide, with or without hydrogen, or of a nitrogen-hydrogen mixture is described. (AEC)

The economics of plastic surgery practices: trends in income, procedure mix, and volume.

PubMed

Krieger, Lloyd M; Lee, Gordon K

2004-07-01

Anecdotally, plastic surgeons have complained of working harder for the same or less income in recent years. They also complain of falling fees for reconstructive surgery and increasing competition for cosmetic surgery. This study examined these notions using the best available data. To gain a better understanding of the current plastic surgery market, plastic surgeon incomes, fees, volume, and relative mix of cosmetic and reconstructive surgery were analyzed between the years 1992 and 2002. To gain a broader perspective, plastic surgeon income trends were then compared with those of other medical specialties and of nonmedical professions. The data show that in real dollars, plastic surgeon incomes have remained essentially steady in recent years, despite plastic surgeons increasing their surgery load by an average of 41 percent over the past 10 years. The overall income trend is similar to that of members of other medical specialties and other nonmedical professionals. The average practice percentage of cosmetic surgery was calculated and found to have increased from 27 percent in 1992 to 58 percent in 2002. This most likely can be explained by the findings that real dollar fees collected for cosmetic surgery have decreased very slightly, whereas those for reconstructive procedures have experienced sharp declines. This study demonstrates that plastic surgeons have adjusted their practice profiles in recent years. They have increased their case loads and shifted their practices toward cosmetic surgery, most likely with the goal of maintaining their incomes. The strategy appears to have been successful in the short term. However, with increasing competition and falling prices for cosmetic surgery, it may represent a temporary bulwark for plastic surgeon incomes unless other steps are taken.

Long-term sorption of metals is similar among plastic types: implications for plastic debris in aquatic environments.

PubMed

Rochman, Chelsea M; Hentschel, Brian T; Teh, Swee J

2014-01-01

Concerns regarding plastic debris and its ability to accumulate large concentrations of priority pollutants in the aquatic environment led us to quantify relationships between different types of mass-produced plastic and metals in seawater. At three locations in San Diego Bay, we measured the accumulation of nine targeted metals (aluminum, chromium, manganese, iron, cobalt, nickel, zinc, cadmium and lead) sampling at 1, 3, 6, 9 and 12 months, to five plastic types: polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), and polypropylene (PP). Accumulation patterns were not consistent over space and time, and in general all types of plastic tended to accumulate similar concentrations of metals. When we did observe significant differences among concentrations of metals at a single sampling period or location in San Diego Bay, we found that HDPE typically accumulated lesser concentrations of metals than the other four polymers. Furthermore, over the 12-month study period, concentrations of all metals increased over time, and chromium, manganese, cobalt, nickel, zinc and lead did not reach saturation on at least one plastic type during the entire 12-month exposure. This suggests that plastic debris may accumulate greater concentrations of metals the longer it remains at sea. Overall, our work shows that a complex mixture of metals, including those listed as priority pollutants by the US EPA (Cd, Ni, Zn and Pb), can be found on plastic debris composed of various plastic types.

Long-Term Sorption of Metals Is Similar among Plastic Types: Implications for Plastic Debris in Aquatic Environments

PubMed Central

Rochman, Chelsea M.; Hentschel, Brian T.; Teh, Swee J.

2014-01-01

Concerns regarding plastic debris and its ability to accumulate large concentrations of priority pollutants in the aquatic environment led us to quantify relationships between different types of mass-produced plastic and metals in seawater. At three locations in San Diego Bay, we measured the accumulation of nine targeted metals (aluminum, chromium, manganese, iron, cobalt, nickel, zinc, cadmium and lead) sampling at 1, 3, 6, 9 and 12 months, to five plastic types: polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), and polypropylene (PP). Accumulation patterns were not consistent over space and time, and in general all types of plastic tended to accumulate similar concentrations of metals. When we did observe significant differences among concentrations of metals at a single sampling period or location in San Diego Bay, we found that HDPE typically accumulated lesser concentrations of metals than the other four polymers. Furthermore, over the 12-month study period, concentrations of all metals increased over time, and chromium, manganese, cobalt, nickel, zinc and lead did not reach saturation on at least one plastic type during the entire 12-month exposure. This suggests that plastic debris may accumulate greater concentrations of metals the longer it remains at sea. Overall, our work shows that a complex mixture of metals, including those listed as priority pollutants by the US EPA (Cd, Ni, Zn and Pb), can be found on plastic debris composed of various plastic types. PMID:24454866

Analysis of Cosmetic Topics on the Plastic Surgery In-Service Training Exam.

PubMed

Silvestre, Jason; Taglienti, Anthony J; Serletti, Joseph M; Chang, Benjamin

2015-08-01

The Plastic Surgery In-Service Training Exam (PSITE) is a multiple-choice examination taken by plastic surgery trainees to provide an assessment of plastic surgery knowledge. The purpose of this study was to evaluate cosmetic questions and determine overlap with national procedural data. Digital syllabi of six consecutive PSITE administrations (2008-2013) were analyzed for cosmetic surgery topics. Questions were classified by taxonomy, focus, anatomy, and procedure. Answer references were tabulated by source. Relationships between tested material and national procedural volume were assessed via Pearson correlation. 301 questions addressed cosmetic topics (26% of all questions) and 20 required image interpretations (7%). Question-stem taxonomy favored decision-making (40%) and recall (37%) skills over interpretation (23%, P < .001). Answers focused on treatments/outcomes (67%) over pathology/anatomy (20%) and diagnoses (13%, P < .001). Tested procedures were largely surgical (85%) and focused on the breast (25%), body (18%), nose (13%), and eye (10%). The most common surgeries were breast augmentation (12%), rhinoplasty (11%), blepharoplasty (10%), and body contouring (6%). Minimally invasive procedures were lasers (5%), neuromodulators (4%), and fillers (3%). Plastic and Reconstructive Surgery (58%), Clinics in Plastic Surgery (7%), and Aesthetic Surgery Journal (6%) were the most cited journals, with a median 5-year publication lag. There was poor correlation between PSITE content and procedural volume data (r(2) = 0.138, P = .539). Plastic surgeons receive routine evaluation of cosmetic surgery knowledge. These data may help optimize clinical and didactic experiences for training in cosmetic surgery. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

Microwave Heating of Crystals with Gold Nanoparticles and Synovial Fluid under Synthetic Skin Patches

PubMed Central

2017-01-01

Gout is a disease with elusive treatment options. Reduction of the size of l-alanine crystals as a model crystal for gouty tophi with the use of a monomode solid-state microwave was examined as a possible therapeutic aid. The effect of microwave heating on l-alanine crystals in the presence of gold nanoparticles (Au NPs) in solution and synovial fluid (SF) in a plastic pouch through a synthetic skin patch was investigated. In this regard, three experimental paradigms were employed: Paradigm 1 includes the effect of variable microwave power (5–10 W) and variable heating time (5–60 s) and Au NPs in water (20 nm size, volume of 10 μL) in a plastic pouch (1 × 2 cm2 in size). Paradigm 2 includes the effect of a variable volume of 20 nm Au NPs in a variable volume of SF up to 100 μL in a plastic pouch at a constant microwave power (10 W) for 30 s. Paradigm 3 includes the effect of constant microwave power (10 W) and microwave heating time (30 s), constant volume of Au NPs (100 μL), and variable size of Au NPs (20–200 nm) placed in a plastic pouch through a synthetic skin patch. In these experiments, an average of 60–100% reduction in the size of an l-alanine crystal (initial size = 450 μm) without damage to the synthetic skin or increasing the temperature of the samples beyond the physiological range was reported. PMID:28983527

A Study on the Effect of Stratified Mixture Formation on Combustion Characteristics in a Constant Volume Combustion Chamber

NASA Astrophysics Data System (ADS)

Lee, Kihyung; Lee, Changhee; Jeoung, Haeyoung

It is well known that a lean burn engine caused by stratified mixture formation has many kinds of advantages to combustion characteristics, such as higher thermal efficiency and lower CO, NOx levels than conventional homogeneous mixture combustion. Although this combustion can achieve low fuel consumption, it produces much unburned hydrocarbon and soot because of inhomogeneity of the charge mixture in the combustion chamber. Therefore, it is necessary to investigate the effect of mixture formation on combustion characteristics in order to obtain the stable lean combustion. In this paper, fundamental studies for stratified combustion were carried out using a constant volume combustion chamber. The effect of mixture formation on the combustion characteristics in the chamber was examined experimentally. In addition, the effect of turbulence on stratified charge combustion process was observed by schlieren photography. From this study, as the swirl intensity increases, (Sv)max is rapidly enhanced and the period of combustion is shortened. We also find that the stratification degree can be quantified by using burning velocity and it was controlled by induced air pressure and turbulent intensity.

Dielectric constant of liquid alkanes and hydrocarbon mixtures

NASA Technical Reports Server (NTRS)

Sen, A. D.; Anicich, V. G.; Arakelian, T.

1992-01-01

The complex dielectric constants of n-alkanes with two to seven carbon atoms have been measured. The measurements were conducted using a slotted-line technique at 1.2 GHz and at atmospheric pressure. The temperature was varied from the melting point to the boiling point of the respective alkanes. The real part of the dielectric constant was found to decrease with increasing temperature and correlate with the change in the molar volume. An upper limit to all the loss tangents was established at 0.001. The complex dielectric constants of a few mixtures of liquid alkanes were also measured at room temperature. For a pentane-octane mixture the real part of the dielectric constant could be explained by the Clausius-Mosotti theory. For the mixtures of n-hexane-ethylacetate and n-hexane-acetone the real part of the dielectric constants could be explained by the Onsager theory extended to mixtures. The dielectric constant of the n-hexane-acetone mixture displayed deviations from the Onsager theory at the highest fractions of acetone. The dipole moments of ethylacetate and acetone were determined for dilute mixtures using the Onsager theory and were found to be in agreement with their accepted gas-phase values. The loss tangents of the mixtures exhibited a linear relationship with the volume fraction for low concentrations of the polar liquids.

Variable Operative Experience in Hand Surgery for Plastic Surgery Residents.

PubMed

Silvestre, Jason; Lin, Ines C; Levin, Lawrence Scott; Chang, Benjamin

Efforts to standardize hand surgery training during plastic surgery residency remain challenging. We analyze the variability of operative hand experience at U.S. plastic surgery residency programs. Operative case logs of chief residents in accredited U.S. plastic surgery residency programs were analyzed (2011-2015). Trends in fold differences of hand surgery case volume between the 10th and 90th percentiles of residents were assessed graphically. Percentile data were used to calculate the number of residents achieving case minimums in hand surgery for 2015. Case logs from 818 plastic surgery residents were analyzed of which a minority were from integrated (35.7%) versus independent/combined (64.3%) residents. Trend analysis of fold differences in case volume demonstrated decreasing variability among procedure categories over time. By 2015, fold differences for hand reconstruction, tendon cases, nerve cases, arthroplasty/arthrodesis, amputation, arterial repair, Dupuytren release, and neoplasm cases were below 10-fold. Congenital deformity cases among independent/combined residents was the sole category that exceeded 10-fold by 2015. Percentile data suggested that approximately 10% of independent/combined residents did not meet case minimums for arterial repair and congenital deformity in 2015. Variable operative experience during plastic surgery residency may limit adequate exposure to hand surgery for certain residents. Future studies should establish empiric case minimums for plastic surgery residents to ensure hand surgery competency upon graduation. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Early Life Stress Differentially Modulates Distinct Forms of Brain Plasticity in Young and Adult Mice

PubMed Central

Reichardt, Wilfried; Clark, Kristin; Geiger, Julia; Gross, Claus M.; Heyer, Andrea; Neagu, Valentin; Bhatia, Harsharan; Atas, Hasan C.; Fiebich, Bernd L.; Bischofberger, Josef; Haas, Carola A.; Normann, Claus

2012-01-01

Background Early life trauma is an important risk factor for many psychiatric and somatic disorders in adulthood. As a growing body of evidence suggests that brain plasticity is disturbed in affective disorders, we examined the short-term and remote effects of early life stress on different forms of brain plasticity. Methodology/Principal Findings Mice were subjected to early deprivation by individually separating pups from their dam in the first two weeks after birth. Distinct forms of brain plasticity were assessed in the hippocampus by longitudinal MR volumetry, immunohistochemistry of neurogenesis, and whole-cell patch-clamp measurements of synaptic plasticity. Depression-related behavior was assessed by the forced swimming test in adult animals. Neuropeptides and their receptors were determined by real-time PCR and immunoassay. Early maternal deprivation caused a loss of hippocampal volume, which returned to normal in adulthood. Adult neurogenesis was unaffected by early life stress. Long-term synaptic potentiation, however, was normal immediately after the end of the stress protocol but was impaired in adult animals. In the forced swimming test, adult animals that had been subjected to early life stress showed increased immobility time. Levels of substance P were increased both in young and adult animals after early deprivation. Conclusion Hippocampal volume was affected by early life stress but recovered in adulthood which corresponded to normal adult neurogenesis. Synaptic plasticity, however, exhibited a delayed impairment. The modulation of synaptic plasticity by early life stress might contribute to affective dysfunction in adulthood. PMID:23071534

Thermal Equilibrium in Plastic and Glass Microscale Containers

ERIC Educational Resources Information Center

Curbelo, Estela; Cerda, Maria F.; Mendez, Eduardo

2007-01-01

The study describes the various thermal equilibrium conditions, which should be taken care for while designing or selecting the plastic and glass microscale containers for physical chemistry experiments. The results show that the thermal equilibrium completely depends on the material of the container for the same volume and thickness.

The Plasticizer Diethylhexyl Phthalate Induces Malformations by Decreasing Fetal Testosterone Synthesis Durin Sexual Differentiation in the Male Rat

EPA Science Inventory

Phthalate esters (PE) like DEHP are high production volume plasticizers used in vinyl floors, food wraps, cosmetics, medical products and toys. In spite of their widespread and long-term use, most PEs have not been adequately tested for transgenerational reproductive toxicity. ...

Pyrolysis of polyethylene mixed with paper and wood: Interaction effects on tar, char and gas yields.

PubMed

Grieco, E M; Baldi, G

2012-05-01

In the present study the interactions between the main constituents of the refuse derived fuel (plastics, paper, and wood) during pyrolysis were studied. Binary mixtures of polyethylene-paper and polyethylene/sawdust have been transformed into pellets and pyrolyzed. Various mixtures with different composition were analyzed and pyrolysis products (tar, gas, and char) were collected. The mixtures of wood/PE and paper/PE have a different behavior. The wood/PE mixtures showed a much reduced interaction of the various compounds because the yields of pyrolysis products of the mixture can be predicted as linear combination of those of the pure components. On the contrary, a strong char yield increase was found at a low heating rate for paper/PE mixtures. In order to explain the results, the ability of wood and paper char to adsorb and convert the products of PE pyrolysis into was studied. Adsorption and desorption tests were performed on the char obtained by paper and wood by using n-hexadecane as a model compound for the heavy products of PE pyrolysis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Volume-change indicator for molding plastic

NASA Technical Reports Server (NTRS)

Heler, W. C.

1979-01-01

Monitor consisting of two concentric disks measures change in volume of charge during compression/displacement molding. Device enables operator to decide whether process pressure and temperature are set properly or whether sufficient material has been placed in mold.

Study of thermite mixture consolidated by the cold gas dynamic spray process

NASA Astrophysics Data System (ADS)

Bacciochini, A.; Maines, G.; Poupart, C.; Akbarnejad, H.; Radulescu, M.; Jodoin, B.; Zhang, F.; Lee, J. J.

2014-05-01

The present study focused on the cold gas dynamic spray process for manufacturing porosity free, finely structured energetic materials with high reactivity and structural integrity. The experiments have focused the reaction between the aluminium and metal oxide, such as Al-CuO system. The consolidation of the materials used the cold gas dynamic spray technique, where the particles are accelerated to high speeds and consolidated via plastic deformation upon impact. Reactive composites are formed in arbitrary shapes with close to zero porosity and without any reactions during the consolidation phase. Reactivity of mixtures has been investigated through flame propagation analysis on cold sprayed samples and compacted powder mixture. Deflagration tests showed the influence of porosity on the reactivity.

In Vivo Stereoisomerization of HBCD Gamma and Alpha Is Tissue and Stereoisomer Specific

USDA-ARS?s Scientific Manuscript database

Hexabromocyclododecane (HBCD) is a flame-retardant used in thermal insulation, plastics and textiles, and the present mouse metabolism studies were initiated to investigate the possible stereoisomerization of individual diastereomers present in the commercial mixture (a, ß, and ') that has been hypo...

Solubility parameters of hypromellose acetate succinate and plasticization in dry coating procedures.

PubMed

Klar, Fabian; Urbanetz, Nora Anne

2016-10-01

Solubility parameters of HPMCAS have not yet been investigated intensively. On this account, total and three-dimensional solubility parameters of HPMCAS were determined by using different experimental as well as computational methods. In addition, solubility properties of HPMCAS in a huge number of solvents were tested and a Teas plot for HPMCAS was created. The total solubility parameter of about 24 MPa(0.5) was confirmed by various procedures and compared with values of plasticizers. Twenty common pharmaceutical plasticizers were evaluated in terms of their suitability for supporting film formation of HPMCAS under dry coating conditions. Therefore, glass transition temperatures of mixtures of polymer and plasticizers were inspected and film formation of potential ones was further investigated in dry coating of pellets. Contact angles of plasticizers on HPMCAS were determined in order to give a hint of achievable coating efficiencies in dry coating, but none was found to spread on HPMCAS. A few common substances, e.g. dimethyl phthalate, glycerol monocaprylate, and polyethylene glycol 400, enabled plasticization of HPMCAS; however, only triethyl citrate and triacetin were found to be suitable for use in dry coating. Addition of acetylated monoglycerides to triacetin increased coating efficiency, which was likewise previously demonstrated for triethyl citrate.

Two Back Stress Hardening Models in Rate Independent Rigid Plastic Deformation

NASA Astrophysics Data System (ADS)

Yun, Su-Jin

In the present work, the constitutive relations based on the combination of two back stresses are developed using the Armstrong-Frederick, Phillips and Ziegler’s type hardening rules. Various evolutions of the kinematic hardening parameter can be obtained by means of a simple combination of back stress rate using the rule of mixtures. Thus, a wide range of plastic deformation behavior can be depicted depending on the dominant back stress evolution. The ultimate back stress is also determined for the present combined kinematic hardening models. Since a kinematic hardening rule is assumed in the finite deformation regime, the stress rate is co-rotated with respect to the spin of substructure obtained by incorporating the plastic spin concept. A comparison of the various co-rotational rates is also included. Assuming rigid plasticity, the continuum body consists of the elastic deformation zone and the plastic deformation zone to form a hybrid finite element formulation. Then, the plastic deformation behavior is investigated under various loading conditions with an assumption of the J2 deformation theory. The plastic deformation localization turns out to be strongly dependent on the description of back stress evolution and its associated hardening parameters. The analysis for the shear deformation with fixed boundaries is carried out to examine the deformation localization behavior and the evolution of state variables.

Mixtures of tense and relaxed state polymerized human hemoglobin regulate oxygen affinity and tissue construct oxygenation

PubMed Central

Belcher, Donald Andrew; Banerjee, Uddyalok; Baehr, Christopher Michael; Richardson, Kristopher Emil; Cabrales, Pedro; Berthiaume, François

2017-01-01

Pure tense (T) and relaxed (R) quaternary state polymerized human hemoglobins (PolyhHbs) were synthesized and their biophysical properties characterized, along with mixtures of T- and R-state PolyhHbs. It was observed that the oxygen affinity of PolyhHb mixtures varied linearly with T-state mole fraction. Computational analysis of PolyhHb facilitated oxygenation of a single fiber in a hepatic hollow fiber (HF) bioreactor was performed to evaluate the oxygenation potential of T- and R-state PolyhHb mixtures. PolyhHb mixtures with T-state mole fractions greater than 50% resulted in hypoxic and hyperoxic zones occupying less than 5% of the total extra capillary space (ECS). Under these conditions, the ratio of the pericentral volume to the perivenous volume in the ECS doubled as the T-state mole fraction increased from 50 to 100%. These results show the effect of varying the T/R-state PolyhHb mole fraction on oxygenation of tissue-engineered constructs and their potential to oxygenate tissues. PMID:29020036

Physical and mechanical properties of mortars containing PET and PC waste aggregates.

PubMed

Hannawi, Kinda; Kamali-Bernard, Siham; Prince, William

2010-11-01

Non-biodegradable plastic aggregates made of polycarbonate (PC) and polyethylene terephthalate (PET) waste are used as partial replacement of natural aggregates in mortar. Various volume fractions of sand 3%, 10%, 20% and 50% are replaced by the same volume of plastic. This paper investigates the physical and mechanical properties of the obtained composites. The main results of this study show the feasibility of the reuse of PC and PET waste aggregates materials as partial volume substitutes for natural aggregates in cementitious materials. Despite of some drawbacks like a decrease in compressive strength, the use of PC and PET waste aggregates presents various advantages. A reduction of the specific weight of the cementitious materials and a significant improvement of their post-peak flexural behaviour are observed. The calculated flexural toughness factors increase significantly with increasing volume fraction of PET and PC-aggregates. Thus, addition of PC and PET plastic aggregates in cementitious materials seems to give good energy absorbing materials which is very interesting for several civil engineering applications like structures subjected to dynamic or impact efforts. The present study has shown quite encouraging results and opened new way for the recycling of PC waste aggregate in cement and concrete composites. Copyright © 2010 Elsevier Ltd. All rights reserved.

Environmentally Induced Epigenetic Transgenerational Inheritance of Ovarian Disease

PubMed Central

Nilsson, Eric; Larsen, Ginger; Manikkam, Mohan; Guerrero-Bosagna, Carlos; Savenkova, Marina I.; Skinner, Michael K.

2012-01-01

The actions of environmental toxicants and relevant mixtures in promoting the epigenetic transgenerational inheritance of ovarian disease was investigated with the use of a fungicide, a pesticide mixture, a plastic mixture, dioxin and a hydrocarbon mixture. After transient exposure of an F0 gestating female rat during embryonic gonadal sex determination, the F1 and F3 generation progeny adult onset ovarian disease was assessed. Transgenerational disease phenotypes observed included an increase in cysts resembling human polycystic ovarian disease (PCO) and a decrease in the ovarian primordial follicle pool size resembling primary ovarian insufficiency (POI). The F3 generation granulosa cells were isolated and found to have a transgenerational effect on the transcriptome and epigenome (differential DNA methylation). Epigenetic biomarkers for environmental exposure and associated gene networks were identified. Epigenetic transgenerational inheritance of ovarian disease states was induced by all the different classes of environmental compounds, suggesting a role of environmental epigenetics in ovarian disease etiology. PMID:22570695

Can niche plasticity promote biodiversity-productivity relationships through increased complementarity?

PubMed

Niklaus, Pascal A; Baruffol, Martin; He, Jin-Sheng; Ma, Keping; Schmid, Bernhard

2017-04-01

Most experimental biodiversity-ecosystem functioning research to date has addressed herbaceous plant communities. Comparably little is known about how forest communities will respond to species losses, despite their importance for global biogeochemical cycling. We studied tree species interactions in experimental subtropical tree communities with 33 distinct tree species mixtures and one, two, or four species. Plots were either exposed to natural light levels or shaded. Trees grew rapidly and were intensely competing above ground after 1.5 growing seasons when plots were thinned and the vertical distribution of leaves and wood determined by separating the biomass of harvested trees into 50 cm height increments. Our aim was to analyze effects of species richness in relation to the vertical allocation of leaf biomass and wood, with an emphasis on bipartite competitive interactions among species. Aboveground productivity increased with species richness. The community-level vertical leaf and wood distribution depended on the species composition of communities. Mean height and breadth of species-level vertical leaf and wood distributions did not change with species richness. However, the extra biomass produced by mixtures compared to monocultures of the component species increased when vertical leaf distributions of monocultures were more different. Decomposition of biodiversity effects with the additive partitioning scheme indicated positive complementarity effects that were higher in light than in shade. Selection effects did not deviate from zero, irrespective of light levels. Vertical leaf distributions shifted apart in mixed stands as consequence of competition-driven phenotypic plasticity, promoting realized complementarity. Structural equation models showed that this effect was larger for species that differed more in growth strategies that were characterized by functional traits. In 13 of the 18 investigated two-species mixtures, both species benefitted relative to intraspecific competition in monoculture. In the remaining five pairwise mixtures, the relative yield gain of one species exceeded the relative yield loss of the other species, resulting in a relative yield total (RYT) exceeding 1. Overall, our analysis indicates that richness-productivity relationships are promoted by interspecific niche complementarity at early stages of stand development, and that this effect is enhanced by architectural plasticity. © 2017 by the Ecological Society of America.

Validation of ATR FT-IR to identify polymers of plastic marine debris, including those ingested by marine organisms

USGS Publications Warehouse

Jung, Melissa R.; Horgen, F. David; Orski, Sara V.; Rodriguez, Viviana; Beers, Kathryn L.; Balazs, George H.; Jones, T. Todd; Work, Thierry M.; Brignac, Kayla C.; Royer, Sarah-Jeanne; Hyrenbach, David K.; Jensen, Brenda A.; Lynch, Jennifer M.

2018-01-01

Polymer identification of plastic marine debris can help identify its sources, degradation, and fate. We optimized and validated a fast, simple, and accessible technique, attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR), to identify polymers contained in plastic ingested by sea turtles. Spectra of consumer good items with known resin identification codes #1–6 and several #7 plastics were compared to standard and raw manufactured polymers. High temperature size exclusion chromatography measurements confirmed ATR FT-IR could differentiate these polymers. High-density (HDPE) and low-density polyethylene (LDPE) discrimination is challenging but a clear step-by-step guide is provided that identified 78% of ingested PE samples. The optimal cleaning methods consisted of wiping ingested pieces with water or cutting. Of 828 ingested plastics pieces from 50 Pacific sea turtles, 96% were identified by ATR FT-IR as HDPE, LDPE, unknown PE, polypropylene (PP), PE and PP mixtures, polystyrene, polyvinyl chloride, and nylon.

Nonlinear dielectric spectroscopy in a fragile plastic crystal

NASA Astrophysics Data System (ADS)

Michl, M.; Bauer, Th.; Lunkenheimer, P.; Loidl, A.

2016-03-01

In this work we provide a thorough examination of the nonlinear dielectric properties of a succinonitrile-glutaronitrile mixture, representing one of the rare examples of a plastic crystal with fragile glassy dynamics. The detected alteration of the complex dielectric permittivity under high fields can be explained considering the heterogeneous nature of glassy dynamics and a field-induced variation of entropy. While the first mechanism was also found in structural glass formers, the latter effect seems to be more pronounced in plastic crystals. Moreover, the third harmonic component of the dielectric susceptibility is reported, revealing a hump-like spectral shape as predicted, e.g., within a model considering cooperative molecular dynamics. If assuming the validity of this model, one can deduce the temperature dependence of the number of correlated molecules Ncorr from these data. In accord with the fragile nature of the glass transition in this plastic crystal, we obtain a relatively strong temperature dependence of Ncorr, in contrast to the much weaker temperature dependence in plastic-crystalline cyclo-octanol, whose glass transition is of strong nature.

Functional Properties of Porous Ti-48.0 at.% Ni Shape Memory Alloy Produced by Self-Propagating High-Temperature Synthesis

NASA Astrophysics Data System (ADS)

Resnina, Natalia; Belyaev, Sergey; Voronkov, Andrew

2018-03-01

The functional behavior of the porous shape memory alloy produced by self-propagating high-temperature synthesis from the Ti-48.0 at.% Ni powder mixture was studied. It was found that a large unelastic strain recovered on unloading and it was not attributed to the pseudoelasticity effect. A decrease in deformation temperatures did not influence the value of strain that recovered on unloading, while the effective modulus decreased from 1.9 to 1.44 GPa. It was found that the porous Ti-48.0 at.% Ni alloy revealed the one-way shape memory effect, where the maximum recoverable strain was 5%. The porous Ti-48.0 at.% Ni alloy demonstrated the transformation plasticity and the shape memory effects on cooling and heating under a stress. An increase in stress did not influence the shape memory effect value, which was equal to 1%. It was shown that the functional properties of the porous alloy were determined by the TiNi phase consisted of the two volumes Ti49.3Ni50.7 and Ti50Ni50 where the martensitic transformation occurred at different temperatures. The results of the study showed that the existence of the Ti49.3Ni50.7 volumes in the porous Ti-48.0 at.% Ni alloy improved the functional properties of the alloy.

Fibre optic sensor for the detection of adulterant traces in coconut oil

NASA Astrophysics Data System (ADS)

Sheeba, M.; Rajesh, M.; Vallabhan, C. P. G.; Nampoori, V. P. N.; Radhakrishnan, P.

2005-11-01

The design and development of a fibre optic evanescent wave refractometer for the detection of trace amounts of paraffin oil and palm oil in coconut oil is presented. This sensor is based on a side-polished plastic optical fibre. At the sensing region, the cladding and a small portion of the core are removed and the fibre nicely polished. The sensing region is fabricated in such a manner that it sits perfectly within a bent mould. This bending of the sensing region enhances its sensitivity. The oil mixture of different mix ratios is introduced into the sensing region and we observed a sharp decrease in the output intensity. The observed variation in the intensity is found to be linear and the detection limit is 2% (by volume) paraffin oil/palm oil in coconut oil. The resolution of this refractometric sensor is of the order of 10-3. Since coconut oil is consumed in large volumes as edible oil in south India, this fibre optic sensor finds great relevance for the detection of adulterants such as paraffin oil or palm oil which are readily miscible in coconut oil. The advantage of this type of sensor is that it is inexpensive and easy to set up. Another attraction of the side-polished fibre is that only a very small amount of analyte is needed and its response time is only 7 s.

Application unit for the administration of contrast gases for pulmonary magnetic resonance imaging: optimization of ventilation distribution for (3) He-MRI.

PubMed

Güldner, M; Becker, St; Wolf, U; Düber, C; Friesenecker, A; Gast, K K; Heil, W; Hoffmann, C; Karpuk, S; Otten, E W; Rivoire, J; Salhi, Z; Scholz, A; Schreiber, L M; Terekhov, M

2015-09-01

MRI of lung airspaces using gases with MR-active nuclei ((3) He, (129) Xe, and (19) F) is an important area of research in pulmonary imaging. The volume-controlled administration of gas mixtures is important for obtaining quantitative information from MR images. State-of-the-art gas administration using plastic bags (PBs) does not allow for a precise determination of both the volume and timing of a (3) He bolus. A novel application unit (AU) was built according to the requirements of the German medical devices law. Integrated spirometers enable the monitoring of the inhaled gas flow. The device is particularly suited for hyperpolarized (HP) gases (e.g., storage and administration with minimal HP losses). The setup was tested in a clinical trial (n = 10 healthy volunteers) according to the German medicinal products law using static and dynamic ventilation HP-(3) He MRI. The required specifications for the AU were successfully realized. Compared to PB-administration, better reproducibility of gas intrapulmonary distribution was observed when using the AU for both static and dynamic ventilation imaging. The new AU meets the special requirements for HP gases, which are storage and administration with minimal losses. Our data suggest that gas AU-administration is superior to manual modes for determining the key parameters of dynamic ventilation measurements. © 2014 Wiley Periodicals, Inc.

Evaluation of the BD BACTEC FX blood volume monitoring system as a continuous quality improvement measure.

PubMed

Coorevits, L; Van den Abeele, A-M

2015-07-01

The yield of blood cultures is proportional to the volume of blood cultured. We evaluated an automatic blood volume monitoring system, recently developed by Becton Dickinson within its BACTEC EpiCenter module, that calculates mean volumes of negative aerobic bottles and generates boxplots and histograms. First, we evaluated the filling degree of 339 aerobic glass blood cultures by calculating the weight-based volume for each bottle. A substantial amount of the bottles (48.3%) were inadequately filled. Evaluation of the accuracy of the monitoring system showed a mean bias of -1.4 mL (-15.4%). Additional evaluation, using the amended software on 287 aerobic blood culture bottles, resulted in an acceptable mean deviation of -0.3 mL (-3.3%). The new software version was also tested on 200 of the recently introduced plastic bottles, which will replace the glass bottles in the near future, showing a mean deviation of +2.8 mL (+26.7%). In conclusion, the mean calculated volumes can be used for the training of a single phlebotomist. However, filling problems appear to be masked when using them for phlebotomist groups or on wards. Here, visual interpretation of boxplots and histograms can serve as a useful tool to observe the spread of the filling degrees and to develop a continuous improvement program. Re-adjustment of the software has proven to be necessary for use with plastic bottles. Due to our findings, BD has developed further adjustments to the software for validated use with plastic bottles, which will be released soon.

Structural and mechanical modifications induced on Zr-based bulk metallic glass by laser shock peening

NASA Astrophysics Data System (ADS)

Zhu, Yunhu; Fu, Jie; Zheng, Chao; Ji, Zhong

2016-12-01

In this study, surface modification of a Zr41.2Ti13.8Cu12.5Ni10Be22.5 (vit1) bulk metallic glass (BMG) has been studied in an effort to improve the mechanical properties by laser shock peening (LSP) treatment. The phase structure, mechanical properties, and microstructural evolution of the as-cast and LSP treated specimens were systematically investigated. It was found that the vit1 BMG still consisted of fully amorphous structure after LSP treatment. Measurements of the heat relaxation indicate that a large amount of free volume is introduced into vit1 BMG during LSP process. LSP treatment causes a decrease of hardness attributable to generation of free volume. The plastic deformation ability of vit1 BMG was investigated under three-point bending conditions. The results demonstrate that the plastic strain of LSP treated specimen is 1.83 times as large as that of the as-cast specimen. The effect of LSP technology on the hardness and plastic deformation ability of vit1 BMG is discussed on the basis of free volume theory. The high dense shear bands on the side surface, the increase of striations and critical shear displacement on the tensile fracture region, and more uniform dimples structure on the compressive fracture region also demonstrate that the plasticity of vit1 BMG can be enhanced by LSP.

Numerical studies of temperature effect on the extrusion fracture and swell of plastic micro-pipe

NASA Astrophysics Data System (ADS)

Ren, Zhong; Huang, Xingyuan; Xiong, Zhihua

2018-03-01

Temperature is a key factor that impacts extrusion forming quality of plastic micro-pipe. In this study, the effect of temperature on extrusion fracture and swell of plastic micro-pipe was investigated by numerical method. Under a certain of the melt’s flow volume, the extrusion pattern, extrusion swelling ratio of melt are obtained under different temperatures. Results show that the extrusion swelling ratio of plastic micro-pipe decreases with increasing of temperature. In order to study the reason of temperature effect, the physical distributions of plastic micro-pipe are gotten. Numerical results show that the viscosity, pressure, stress value of melt are all decreased with the increasing of temperature, which leads to decrease the extrusion swell and fracture phenomenon for the plastic micro-pipe.

Thermal infrared spectral analysis of compacted fine-grained mineral mixtures: implications for spectral interpretation of lithified sedimentary materials on Mars

NASA Astrophysics Data System (ADS)

Pan, C.; Rogers, D.

2012-12-01

Characterizing the thermal infrared (TIR) spectral mixing behavior of compacted fine-grained mineral assemblages is necessary for facilitating quantitative mineralogy of sedimentary surfaces from spectral measurements. Previous researchers have demonstrated that TIR spectra from igneous and metamorphic rocks as well as coarse-grained (>63 micron) sand mixtures combine in proportion to their volume abundance. However, the spectral mixing behavior of compacted, fine-grained mineral mixtures that would be characteristic of sedimentary depositional environments has received little attention. Here we characterize the spectral properties of pressed pellet samples of <10 micron mineral mixtures to 1) assess linearity of spectral combinations, 2) determine whether there are consistent over- or under-estimations of different types of minerals in spectral models and 3) determine if model accuracy can be improved by including both fine- and coarse-grained end-members. Major primary and secondary minerals found on the Martian surface including feldspar, pyroxene, smectite, sulfate and carbonate were crushed with an agate mortar and pestle and centrifuged to obtain less than 10 micron size. Pure phases and mixtures of two, three and four components were made in varying proportions by volume. All of the samples were pressed into pellets at 15000PSI to minimize volume scattering. Thermal infrared spectra of pellets were measured in the Vibrational Spectroscopy Laboratory at Stony Brook University with a Thermo Fisher Nicolet 6700 Fourier transform infrared Michelson interferometer from ~225 to 2000 cm-1. Our preliminary results indicate that some pelletized samples have contributions from volume scattering, which leads to non-linear spectral combinations. It is not clear if the transparency features (which arise from multiple surface reflections of incident photons) are due to minor clinging fines on an otherwise specular pellet surface or to partially transmitted energy through optically thin grains in the compacted mixture. Inclusion of loose powder (<10 μm) sample spectra improves mineral abundance estimates for some mixtures. In general, mineral abundances are predicted to within +/- 10% (absolute) for approximately 60% of our samples; thus far, there are no clear trends in which cases produce better model results. With the exception of pyroxene/feldspar ratios being consistently overestimated, there are no consistent trends in over- or under-estimation of minerals. The results described here are based on the unsubstantiated assumption that areal abundance on the pellet surface is equal to the volume abundance. Thus future work will include micro-imaging of our samples to constrain areal abundance. We will also prepareclay mixtures using a wetting/drying sequence rather than pressure, and expand our set of samples to include additional mixture combinations to further characterize the spectral behavior of compacted mixtures. This work will be directly applicable to analysis of TES and Mini-TES data of lithified sedimentary deposits.

Modeling Plastic Shocks in Periodic Laminates with Gradient Plasticity Theories

DTIC Science & Technology

2007-08-26

stainless steel (SS)) layers with volume fractions being respectively, LLf /11= , LLf /22= . (3) Material characteristics of the...characteristics of polycarbonate and stainless steel Poisson ratio Elastic shear modulus Mass density PC...Polycarbonate) 0.37 0.94 Gpa 1190 kg/m3 SS ( Stainless steel ) 0.29 77 Gpa 7890 kg

A Student-Made Inexpensive Multichannel Pipet

ERIC Educational Resources Information Center

Dragojlovic, Veljko

2009-01-01

An inexpensive multichannel pipet designed to deliver small volumes of liquid simultaneously to wells in a multiwell plate can be prepared by students in a single laboratory period. The multichannel pipet is made of disposable plastic 1 mL syringes and drilled plastic plates, which are used to make plunger and barrel assemblies. Application of the…

Low-grade inflammation disrupts structural plasticity in the human brain.

PubMed

Szabó, C; Kelemen, O; Kéri, S

2014-09-05

Increased low-grade inflammation is thought to be associated with several neuropsychiatric disorders characterized by decreased neuronal plasticity. The purpose of the present study was to investigate the relationship between structural changes in the human brain during cognitive training and the intensity of low-grade peripheral inflammation in healthy individuals (n=56). A two-month training (30 min/day) with a platformer video game resulted in a significantly increased volume of the right hippocampal formation. The number of stressful life events experienced during the past year was associated with less pronounced enlargement of the hippocampus. However, the main predictor of hippocampal volume expansion was the relative peripheral expression of Nuclear Factor-κB (NF-κB), a transcription factor playing a central role in the effect of pro-inflammatory cytokines. Interleukin-6 (IL-6) and C-reactive protein levels were not related to hippocampal plasticity when NF-κB was taken into consideration. These results suggest that more intensive peripheral inflammation is associated with weaker neuronal plasticity during cognitive training. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Large-volume excitation of air, argon, nitrogen and combustible mixtures by thermal jets produced by nanosecond spark discharges

NASA Astrophysics Data System (ADS)

Stepanyan, Sergey; Hayashi, Jun; Salmon, Arthur; Stancu, Gabi D.; Laux, Christophe O.

2017-04-01

This work presents experimental observations of strong expanding thermal jets following the application of nanosecond spark discharges. These jets propagate in a toroidal shape perpendicular to the interelectrode axis, with high velocities of up to 30 m s-1 and over distances of the order of a cm. Their propagation length is much larger than the thermal expansion region produced by the conventional millisecond sparks used in car engine ignition, thus greatly improving the volumetric excitation of gas mixtures. The shape and velocity of the jets is found to be fairly insensitive to the shape of the electrodes. In addition, their spatial extent is found to increase with the number of nanosecond sparks and with the discharge voltage, and to decrease slightly with the pressure between 1 and 7 atm at constant applied voltage. Finally, this thermal jet phenomenon is observed in experiments conducted with many types of gas mixtures, including air, nitrogen, argon, and combustible CH4/air mixtures. This makes nanosecond repetitively pulsed discharges particularly attractive for aerodynamic flow control or plasma-assisted combustion because of their ability to excite large volumes of gas, typically about 100 times the volume of the discharge.

Carbon dioxide remediation via oxygen-enriched combustion using dense ceramic membranes

DOEpatents

Balachandran, Uthamalingam; Bose, Arun C.; McIlvried, Howard G.

2001-01-01

A method of combusting pulverized coal by mixing the pulverized coal and an oxidant gas to provide a pulverized coal-oxidant gas mixture and contacting the pulverized coal-oxidant gas mixture with a flame sufficiently hot to combust the mixture. An oxygen-containing gas is passed in contact with a dense ceramic membrane of metal oxide material having electron conductivity and oxygen ion conductivity that is gas-impervious until the oxygen concentration on one side of the membrane is not less than about 30% by volume. An oxidant gas with an oxygen concentration of not less than about 30% by volume and a CO.sub.2 concentration of not less than about 30% by volume and pulverized coal is contacted with a flame sufficiently hot to combust the mixture to produce heat and a flue gas. One dense ceramic membrane disclosed is selected from the group consisting of materials having formulae SrCo.sub.0.8 Fe.sub.0.2 O.sub.x, SrCo.sub.0.5 FeO.sub.x and La.sub.0.2 Sr.sub.0.8 Co.sub.0.4 Fe.sub.0.6 O.sub.x.

Thermal shock resistance ceramic insulator

DOEpatents

Morgan, Chester S.; Johnson, William R.

1980-01-01

Thermal shock resistant cermet insulators containing 0.1-20 volume % metal present as a dispersed phase. The insulators are prepared by a process comprising the steps of (a) providing a first solid phase mixture of a ceramic powder and a metal precursor; (b) heating the first solid phase mixture above the minimum decomposition temperature of the metal precursor for no longer than 30 minutes and to a temperature sufficiently above the decomposition temperature to cause the selective decomposition of the metal precursor to the metal to provide a second solid phase mixture comprising particles of ceramic having discrete metal particles adhering to their surfaces, said metal particles having a mean diameter no more than 1/2 the mean diameter of the ceramic particles, and (c) densifying the second solid phase mixture to provide a cermet insulator having 0.1-20 volume % metal present as a dispersed phase.

Isolating cells from female/male blood mixtures using florescence in situ hybridization combined with low volume PCR and its application in forensic science.

PubMed

Feng, Lei; Li, Cai-Xia; Han, Jun-Ping; Xu, Cheng; Hu, Lan

2015-11-01

To obtain single-source short tandem repeat (STR) profiles in trace female/male blood mixture samples, we combined florescence in situ hybridization (FISH), laser microdissection, and low volume PCR (LV-PCR) to isolate male/female cells and improve sensitivity. The results showed that isolation of as few as 10 leukocytes was sufficient to yield full STR profiles in fresh female or male blood samples for 32 independent tests with a low additional alleles rate (3.91%) and drop-out alleles rate (5.01%). Moreover, this procedure was tested in two fresh blood mixture series at three ratios (1:5, 1:10, and 1:20), two mock female/male blood mixture casework samples, and one practical casework sample. Male and female STR profiles were successfully detected in all of these samples, showing that this procedure could be used in forensic casework in the future.

Hydrologic risk analysis in the Yangtze River basin through coupling Gaussian mixtures into copulas

NASA Astrophysics Data System (ADS)

Fan, Y. R.; Huang, W. W.; Huang, G. H.; Li, Y. P.; Huang, K.; Li, Z.

2016-02-01

In this study, a bivariate hydrologic risk framework is proposed through coupling Gaussian mixtures into copulas, leading to a coupled GMM-copula method. In the coupled GMM-Copula method, the marginal distributions of flood peak, volume and duration are quantified through Gaussian mixture models and the joint probability distributions of flood peak-volume, peak-duration and volume-duration are established through copulas. The bivariate hydrologic risk is then derived based on the joint return period of flood variable pairs. The proposed method is applied to the risk analysis for the Yichang station on the main stream of the Yangtze River, China. The results indicate that (i) the bivariate risk for flood peak-volume would keep constant for the flood volume less than 1.0 × 105 m3/s day, but present a significant decreasing trend for the flood volume larger than 1.7 × 105 m3/s day; and (ii) the bivariate risk for flood peak-duration would not change significantly for the flood duration less than 8 days, and then decrease significantly as duration value become larger. The probability density functions (pdfs) of the flood volume and duration conditional on flood peak can also be generated through the fitted copulas. The results indicate that the conditional pdfs of flood volume and duration follow bimodal distributions, with the occurrence frequency of the first vertex decreasing and the latter one increasing as the increase of flood peak. The obtained conclusions from the bivariate hydrologic analysis can provide decision support for flood control and mitigation.

Some comments on thermodynamic consistency for equilibrium mixture equations of state

DOE PAGES

Grove, John W.

2018-03-28

We investigate sufficient conditions for thermodynamic consistency for equilibrium mixtures. Such models assume that the mass fraction average of the material component equations of state, when closed by a suitable equilibrium condition, provide a composite equation of state for the mixture. Here, we show that the two common equilibrium models of component pressure/temperature equilibrium and volume/temperature equilibrium (Dalton, 1808) define thermodynamically consistent mixture equations of state and that other equilibrium conditions can be thermodynamically consistent provided appropriate values are used for the mixture specific entropy and pressure.

Cluster kinetics model for mixtures of glassformers

NASA Astrophysics Data System (ADS)

Brenskelle, Lisa A.; McCoy, Benjamin J.

2007-10-01

For glassformers we propose a binary mixture relation for parameters in a cluster kinetics model previously shown to represent pure compound data for viscosity and dielectric relaxation as functions of either temperature or pressure. The model parameters are based on activation energies and activation volumes for cluster association-dissociation processes. With the mixture parameters, we calculated dielectric relaxation times and compared the results to experimental values for binary mixtures. Mixtures of sorbitol and glycerol (seven compositions), sorbitol and xylitol (three compositions), and polychloroepihydrin and polyvinylmethylether (three compositions) were studied.

Commander Lousma stows trash bags in middeck CO2 Absorber Stowage volume

NASA Technical Reports Server (NTRS)

1982-01-01

Commander Lousma uses his body as a zero gravity garbage compactor to stow plastic bags full of empty containers and trash in the Carbon Dioxide (CO2) Absorber Stowage volume in front of the airlock hatch.

Cosmetic surgery volume and its correlation with the major US stock market indices.

PubMed

Gordon, Chad R; Pryor, Landon; Afifi, Ahmed M; Benedetto, Paul X; Langevin, C J; Papay, Francis; Yetman, Randall; Zins, James E

2010-01-01

As a consumer-driven industry, cosmetic plastic surgery is subject to ebbs and flows as the economy changes. There have been many predictions about the short, intermediate, and long-term impact on cosmetic plastic surgery as a result of difficulties in the current economic climate, but no studies published in the literature have quantified a direct correlation. The authors investigate a possible correlation between cosmetic surgery volume and the economic trends of the three major US stock market indices. A volume analysis for the time period from January 1992 to October 2008 was performed (n = 7360 patients, n = 8205 procedures). Four cosmetic procedures-forehead lift (FL), rhytidectomy (Rh), breast augmentation (BA), and liposuction (Li)-were chosen; breast reduction (BRd), breast reconstruction (BRc), and carpal tunnel release (CTR) were selected for comparison. Case volumes for each procedure and fiscal quarter were compared to the trends of the S&P 500, Dow Jones (DOW), and NASDAQ (NASD) indices. Pearson correlation statistics were used to evaluate a relationship between the market index trends and surgical volume. P values <.05 were considered statistically significant. Three of the four cosmetic surgery procedures investigated (Rh, n = 1540; Li, n = 1291; BA, n = 1959) demonstrated a direct (ie, positive) statistical correlation to all three major market indices. FL (n =312) only correlated to the NASD (P = .021) and did not reach significance with the S&P 500 (P = .077) or DOW (P = .14). BRd and BRc demonstrated a direct correlation to two of the three stock market indices, whereas CTR showed an inverse (ie, negative) correlation to two of the three indices. This study, to our knowledge, is the first to suggest a direct correlation of four cosmetic and two reconstructive plastic surgery procedures to the three major US stock market indices and further emphasizes the importance of a broad-based plastic surgery practice in times of economic recession.

Installation Restoration Program. Phase 2. Confirmation/Quantification Stage 2, Moody Air Force Base, Georgia. Appendices. Volume 1

DTIC Science & Technology

1988-11-01

Light gray NB, clayey (kaolin). Poetv al - quartz mad to fine sand, mod. (0 Locking Cap plastic , saturated. 3 COMPILED BY B. Painter (EWM) t DATE 11-21...Painter (EUM) -SAMPLE PNTAINSOIL DESCRIIPTION COMMENTS ZTEST NAME. GRADATION OR PLASTICITY ,. DEPTH Of CASING, W ~ 1NPARTICLE SIZE DISTRIBUTION. COLOR...L. Grayish orange 10 YR 7/4. quart. RNDEVAI: very tine Sandy clay, dense, DIAMETER: 2-inrh Srhe So PVC moderately plastics dry. DEPTH: 2 - fenot[ 1

Rice stubble as a new biopolymer source to produce carboxymethyl cellulose-blended films.

PubMed

Rodsamran, Pattrathip; Sothornvit, Rungsinee

2017-09-01

Rice stubble is agricultural waste consisting of cellulose which can be converted to carboxymethyl cellulose from rice stubble (CMCr) as a potential biomaterial. Plasticizer types (glycerol and olive oil) and their contents were investigated to provide flexibility for use as food packaging material. Glycerol content enhanced extensibility, while olive oil content improved the moisture barrier of films. Additionally, CMCr showed potential as a replacement for up to 50% of commercial CMC without any changes in mechanical and permeability properties. A mixture of plasticizers (10% glycerol and 10% olive oil) provided blended film with good water barrier and mechanical properties comparable with 20% individual plasticizer. Principle component (PC) analysis with 2 PCs explained approximately 81% of the total variance, was a useful tool to select a suitable plasticizer ratio for blended film production. Therefore, CMCr can be used to form edible film and coating as a renewable environmentally friendly packaging material. Copyright © 2017 Elsevier Ltd. All rights reserved.

Waste to Energy Conversion by Stepwise Liquefaction, Gasification and "Clean" Combustion of Pelletized Waste Polyethylene for Electric Power Generation---in a Miniature Steam Engine

NASA Astrophysics Data System (ADS)

Talebi Anaraki, Saber

The amounts of waste plastics discarded in developed countries are increasing drastically, and most are not recycled. The small fractions of the post-consumer plastics which are recycled find few new uses as their quality is degraded; they cannot be reused in their original applications. However, the high energy density of plastics, similar to that of premium fuels, combined with the dwindling reserves of fossil fuels make a compelling argument for releasing their internal energy through combustion, converting it to thermal energy and, eventually, to electricity through a heat engine. To minimize the emission of pollutants this energy conversion is done in two steps, first the solid waste plastics undergo pyrolytic gasification and, subsequently, the pyrolyzates (a mixture of hydrocarbons and hydrogen) are blended with air and are burned "cleanly" in a miniature power plant. This plant consists of a steam boiler, a steam engine and an electricity generator.

Equilibrium model analysis of waste plastics gasification using CO2 and steam.

PubMed

Kannan, P; Lakshmanan, G; Al Shoaibi, A; Srinivasakannan, C

2017-12-01

Utilization of carbon dioxide (CO 2 ) in thermochemical treatment of waste plastics may significantly help to improve CO 2 recycling, thus simultaneously curtailing dioxins/furans and CO 2 emissions. Although CO 2 is not such an effective gasifying agent as steam, a few investigations have explored the utilization of CO 2 in conjunction with steam to achieve somewhat higher carbon conversion. This work presents a comparative evaluation study of CO 2 and steam gasification of a typical post-consumer waste plastics mixture using an Aspen Plus equilibrium model. The effect of flow rate of gasifying medium (CO 2 and/or steam) and gasification temperature on product gas composition, carbon conversion, and cold gas efficiency has been analyzed. Simulation results demonstrate that CO 2 can serve as a potential gasifying agent for waste plastics gasification. The resulting product gas was rich in CO whereas CO 2 -steam blends yield a wider H 2 /CO ratio, thus extending the applications of the product gas.

Electrochemical cell and negative electrode therefor

DOEpatents

Kaun, Thomas D.

1982-01-01

A secondary electrochemical cell with the positive and negative electrodes separated by a molten salt electrolyte with the negative electrode comprising a particulate mixture of lithium-aluminum alloy and electrolyte and an additive selected from graphitized carbon, Raney iron or mixtures thereof. The lithium-aluminum alloy is present in the range of from about 45 to about 80 percent by volume of the negative electrode, and the electrolyte is present in an amount not less than about 10 percent by volume of the negative electrode. The additive of graphitized carbon is present in the range of from about 1 to about 10 percent by volume of the negative electrode, and the Raney iron additive is present in the range of from about 3 to about 10 percent by volume of the negative electrode.

Densities, Ultrasonic Speeds, and Excess Properties of Binary Mixtures of Diethylene Glycol with 1-Butanol, 2-Butanol, and 1,4-Butanediol at Different Temperatures

NASA Astrophysics Data System (ADS)

Ali, Anwar; Ansari, Sana; Uzair, Sahar; Tasneem, Shadma; Nabi, Firdosa

2015-11-01

Densities ρ and ultrasonic speeds u for pure diethylene glycol, 1-butanol, 2-butanol, and 1,4-butanediol and for their binary mixtures over the entire composition range were measured at 298.15 K, 303.15 K, 308.15 K, and 313.15 K. Using these data, the excess molar volumes, VE_m, deviations in isentropic compressibilities, {\\varDelta }ks, apparent molar volumes, V_{φi} , partial molar volumes, overline{V}_{m,i} , and excess partial molar volumes, overline{V}_{m,i}^E , have been calculated over the entire composition range, and also the excess partial molar volumes of the components at infinite dilution, overline{V}_{m,i}^{E,infty } have been calculated. The excess functions have been correlated using the Redlich-Kister equation at different temperatures. The variations of these derived parameters with composition and temperature are presented graphically.

How the dispersion of magnesium oxide nanoparticles effects on the viscosity of water-ethylene glycol mixture: Experimental evaluation and correlation development

NASA Astrophysics Data System (ADS)

Afrand, Masoud; Abedini, Ehsan; Teimouri, Hamid

2017-03-01

In this paper, the effect of dispersion of magnesium oxide nanoparticles on viscosity of a mixture of water and ethylene glycol (50-50% vol.) was examined experimentally. Experiments were performed for various nanofluid samples at different temperatures and shear rates. Measurements revealed that the nanofluid samples with volume fractions of less than 1.5% had Newtonian behavior, while the sample with volume fraction of 3% showed non-Newtonian behavior. Results showed that the viscosity of nanofluids enhanced with increasing nanoparticles volume fraction and decreasing temperature. Results of sensitivity analysis revealed that the viscosity sensitivity of nanofluid samples to temperature at higher volume fractions is more than that of at lower volume fractions. Finally, because of the inability of the existing model to predict the viscosity of MgO/EG-water nanofluid, an experimental correlation has been proposed for predicting the viscosity of the nanofluid.

Lax-Wendroff and TVD finite volume methods for unidimensional thermomechanical numerical simulations of impacts on elastic-plastic solids

NASA Astrophysics Data System (ADS)

Heuzé, Thomas

2017-10-01

We present in this work two finite volume methods for the simulation of unidimensional impact problems, both for bars and plane waves, on elastic-plastic solid media within the small strain framework. First, an extension of Lax-Wendroff to elastic-plastic constitutive models with linear and nonlinear hardenings is presented. Second, a high order TVD method based on flux-difference splitting [1] and Superbee flux limiter [2] is coupled with an approximate elastic-plastic Riemann solver for nonlinear hardenings, and follows that of Fogarty [3] for linear ones. Thermomechanical coupling is accounted for through dissipation heating and thermal softening, and adiabatic conditions are assumed. This paper essentially focuses on one-dimensional problems since analytical solutions exist or can easily be developed. Accordingly, these two numerical methods are compared to analytical solutions and to the explicit finite element method on test cases involving discontinuous and continuous solutions. This allows to study in more details their respective performance during the loading, unloading and reloading stages. Particular emphasis is also paid to the accuracy of the computed plastic strains, some differences being found according to the numerical method used. Lax-Wendoff two-dimensional discretization of a one-dimensional problem is also appended at the end to demonstrate the extensibility of such numerical scheme to multidimensional problems.

Neutron and gamma detector using an ionization chamber with an integrated body and moderator

DOEpatents

Ianakiev, Kiril D.; Swinhoe, Martyn T.; Lestone, John Paul

2006-07-18

A detector for detecting neutrons and gamma radiation includes a cathode that defines an interior surface and an interior volume. A conductive neutron-capturing layer is disposed on the interior surface of the cathode and a plastic housing surrounds the cathode. A plastic lid is attached to the housing and encloses the interior volume of the cathode forming an ionization chamber, into the center of which an anode extends from the plastic lid. A working gas is disposed within the ionization chamber and a high biasing voltage is connected to the cathode. Processing electronics are coupled to the anode and process current pulses which are converted into Gaussian pulses, which are either counted as neutrons or integrated as gammas, in response to whether pulse amplitude crosses a neutron threshold. The detector according to the invention may be readily fabricated into single or multilayer detector arrays.

Feasibility Study on S-Band Microwave Radiation and 3D-Thermal Infrared Imaging Sensor-Aided Recognition of Polymer Materials from End-of-Life Vehicles

PubMed Central

Huang, Jiu; Zhu, Zhuangzhuang; Tian, Chuyuan; Bian, Zhengfu

2018-01-01

With the increase the worldwide consumption of vehicles, end-of-life vehicles (ELVs) have kept rapidly increasing in the last two decades. Metallic parts and materials of ELVs can be easily reused and recycled, but the automobile shredder residues (ASRs), of which elastomer and plastic materials make up the vast majority, are difficult to recycle. ASRs are classified as hazardous materials in the main industrial countries, and are required to be materially recycled up to 85–95% by mass until 2020. However, there is neither sufficient theoretical nor practical experience for sorting ASR polymers. In this research, we provide a novel method by using S-Band microwave irradiation together with 3D scanning as well as infrared thermal imaging sensors for the recognition and sorting of typical plastics and elastomers from the ASR mixture. In this study, an industrial magnetron array with 2.45 GHz irradiation was utilized as the microwave source. Seven kinds of ELV polymer (PVC, ABS, PP, EPDM, NBR, CR, and SBR) crushed scrap residues were tested. After specific power microwave irradiation for a certain time, the tested polymer materials were heated up to different extents corresponding to their respective sensitivities to microwave irradiation. Due to the variations in polymer chemical structure and additive agents, polymers have different sensitivities to microwave radiation, which leads to differences in temperature rises. The differences of temperature increase were obtained by a thermal infrared sensor, and the position and geometrical features of the tested scraps were acquired by a 3D imaging sensor. With this information, the scrap material could be recognized and then sorted. The results showed that this method was effective when the tested polymer materials were heated up to more than 30 °C. For full recognition of the tested polymer scraps, the minimum temperature variations of 5 °C and 10.5 °C for plastics and elastomers were needed, respectively. The sorting efficiency was independent of particle sizes but depended on the power and time of the microwave irradiation. Generally, more than 75% (mass) of the tested polymer materials could be successfully recognized and sorted under an irradiation power of 3 kW. Plastics were much more insensitive to microwave irradiation than elastomers. With this method, the tested mixture of the plastic group (PVC, ABS, PP) and the mixture of elastomer group (EPDM, NBR, CR, and SBR) could be fully separated with an efficiency of 100%. PMID:29702564

Feasibility Study on S-Band Microwave Radiation and 3D-Thermal Infrared Imaging Sensor-Aided Recognition of Polymer Materials from End-of-Life Vehicles.

PubMed

Huang, Jiu; Zhu, Zhuangzhuang; Tian, Chuyuan; Bian, Zhengfu

2018-04-27

With the increase the worldwide consumption of vehicles, end-of-life vehicles (ELVs) have kept rapidly increasing in the last two decades. Metallic parts and materials of ELVs can be easily reused and recycled, but the automobile shredder residues (ASRs), of which elastomer and plastic materials make up the vast majority, are difficult to recycle. ASRs are classified as hazardous materials in the main industrial countries, and are required to be materially recycled up to 85⁻95% by mass until 2020. However, there is neither sufficient theoretical nor practical experience for sorting ASR polymers. In this research, we provide a novel method by using S-Band microwave irradiation together with 3D scanning as well as infrared thermal imaging sensors for the recognition and sorting of typical plastics and elastomers from the ASR mixture. In this study, an industrial magnetron array with 2.45 GHz irradiation was utilized as the microwave source. Seven kinds of ELV polymer (PVC, ABS, PP, EPDM, NBR, CR, and SBR) crushed scrap residues were tested. After specific power microwave irradiation for a certain time, the tested polymer materials were heated up to different extents corresponding to their respective sensitivities to microwave irradiation. Due to the variations in polymer chemical structure and additive agents, polymers have different sensitivities to microwave radiation, which leads to differences in temperature rises. The differences of temperature increase were obtained by a thermal infrared sensor, and the position and geometrical features of the tested scraps were acquired by a 3D imaging sensor. With this information, the scrap material could be recognized and then sorted. The results showed that this method was effective when the tested polymer materials were heated up to more than 30 °C. For full recognition of the tested polymer scraps, the minimum temperature variations of 5 °C and 10.5 °C for plastics and elastomers were needed, respectively. The sorting efficiency was independent of particle sizes but depended on the power and time of the microwave irradiation. Generally, more than 75% (mass) of the tested polymer materials could be successfully recognized and sorted under an irradiation power of 3 kW. Plastics were much more insensitive to microwave irradiation than elastomers. With this method, the tested mixture of the plastic group (PVC, ABS, PP) and the mixture of elastomer group (EPDM, NBR, CR, and SBR) could be fully separated with an efficiency of 100%.

Investigation of the plastic fracture of high-strength aluminum alloys

NASA Technical Reports Server (NTRS)

Van Stone, R. H.; Merchant, R. H.; Low, J. R., Jr.

1974-01-01

In a study of plastic fracture in five high-strength aluminum alloys (2014, 2024, 2124, 7075, and 7079), it has been shown that fracture toughness is affected primarily by the size and volume fraction of the larger (2 to 10 microms) second-phase particles. Certain of these particles crack at small plastic strains, nucleating voids which, with further plastic strain, coalesce to cause fracture. Not all second-phase particles crack at small plastic strains, and qualitative analysis of those which are primarily responsible for void nucleation shows that they contain iron or silicon or both. This result suggests that a reduction in the iron and silicon impurity content of the alloys should improve fracture toughness without loss of strength.

Mixtures of charged colloid and neutral polymer: Influence of electrostatic interactions on demixing and interfacial tension

NASA Astrophysics Data System (ADS)

Denton, Alan R.; Schmidt, Matthias

2005-06-01

The equilibrium phase behavior of a binary mixture of charged colloids and neutral, nonadsorbing polymers is studied within free-volume theory. A model mixture of charged hard-sphere macroions and ideal, coarse-grained, effective-sphere polymers is mapped first onto a binary hard-sphere mixture with nonadditive diameters and then onto an effective Asakura-Oosawa model [S. Asakura and F. Oosawa, J. Chem. Phys. 22, 1255 (1954)]. The effective model is defined by a single dimensionless parameter—the ratio of the polymer diameter to the effective colloid diameter. For high salt-to-counterion concentration ratios, a free-volume approximation for the free energy is used to compute the fluid phase diagram, which describes demixing into colloid-rich (liquid) and colloid-poor (vapor) phases. Increasing the range of electrostatic interactions shifts the demixing binodal toward higher polymer concentration, stabilizing the mixture. The enhanced stability is attributed to a weakening of polymer depletion-induced attraction between electrostatically repelling macroions. Comparison with predictions of density-functional theory reveals a corresponding increase in the liquid-vapor interfacial tension. The predicted trends in phase stability are consistent with observed behavior of protein-polysaccharide mixtures in food colloids.

[Isolation and purification of BMScs of GFP transgenic mouse using the method of adhering to cuture plastic in different time].

PubMed

Li, Fu-Qiang; Zhou, Hong-Ying; Yang, Hui-Lun; Xiang, Tao; Mei, Yan; Hu, Huo-Zhen; Wang, Ting-Hua

2006-03-01

To adopt the method of adhering to culture plastic in different time for cultivating and purifying BMSCs of green fluorescent protein (GFP) transgenic mice. Bone marrow cells isolated from GFP transgenic mice are directly planted in culture flask and an exchange of the total volume medium is made at different time. Then the cells adhering to culture plastic are differently counted according to the cell types and are examined by immunohistochemistry using the antibodies of CD44, CD45 and CD54 in three days. Moreover, the cells after the exchange of the total volume medium in 4 hours, 8 hours and 24 hours are selected and successively subcultured down to the fifth passage. Then the result of amplification is calculated and the cells are examined by immunohistochemistry using the antibodies of CD44, CD45 and CD54. With the extending of the time for the first exchange of medium, the density of cells adhering to culture plastic increased accordingly, but the BMSCs proportion decreased. The cells after first exchange of medium in 4 hours had high BMSCs proportion but low BMSCs density, and the cells in 24 hours had high BMSCs density and low BMSCs proportion. However, the cells in 8-10 hours had high BMSCs density and also high BMSCs proportion. The subcultured BMSCs could stably express GFP. The method of adhering to culture plastic in different time for cultivating and purifying BMSCs of GFP transgenic mice is effective. It is suitable to make the first exchange of total volume medium in 8-10 hours. The subcultured cell has the capacity for amplification and will probably be a seed cell for the research of tissue engineering and gene therapy.

Neutronic reactor thermal shield

DOEpatents

Wende, Charles W. J.

1976-06-15

1. The method of operating a water-cooled neutronic reactor having a graphite moderator which comprises flowing a gaseous mixture of carbon dioxide and helium, in which the helium comprises 40-60 volume percent of the mixture, in contact with the graphite moderator.

PBDES: TOXICOLOGY UPDATE

EPA Science Inventory

Polybrominated diphenyl ethers (PBDEs) have been major commercial products used as flame retardants. While two of the commercial mixtures, Penta and Octa, have either been withdrawn or banned in Europe and the US respectively, the largest volume mixture, Deca, continues to be wi...

Mechanism for Increasing the Pressure in an Oil Well by a Combustible Oxidizing Liquid Mixture

NASA Astrophysics Data System (ADS)

Melik-Gaikazov, G. V.

2014-09-01

A method of estimating the pressure pulse arising in a deep oil well as a result of the thermal explosion of a combustible oxidizing liquid mixture in it is presented. It was established that less than 10% of this mixture is expended for the formation of a pressure pulse in this well. The conditions under which a tubing string positioned in such a well experiences a plastic bending and its walls are crumpled were determined. The maximum admissible difference between the pressures at the walls of this tube were calculated, and axial compression loads were related to critical forces of different orders. It is shown that, when the indicated tube is submerged in the liquid in the well, its resistance to a short-time axial compression load increases.

Investigation of plastic debris ingestion by four species of sea turtles collected as bycatch in pelagic Pacific longline fisheries

USGS Publications Warehouse

Clukey, Katherine E.; Lepczyk, Christopher A.; Balazs, George H.; Work, Thierry M.; Lynch, Jennifer M.

2017-01-01

Ingestion of marine debris is an established threat to sea turtles. The amount, type, color and location of ingested plastics in the gastrointestinal tracts of 55 sea turtles from Pacific longline fisheries from 2012 to 2016 were quantified, and compared across species, turtle length, body condition, sex, capture location, season and year. Six approaches for quantifying amounts of ingested plastic strongly correlated with one another and included: number of pieces, mass, volume and surface area of plastics, ratio of plastic mass to body mass, and percentage of the mass of gut contents consisting of plastic. All olive ridley (n = 37), 90% of green (n = 10), 80% of loggerhead (n = 5) and 0% of leatherback (n = 3) turtles had ingested plastic; green turtles ingested significantly more than olive ridleys. Most debris was in the large intestines. No adverse health impacts (intestinal lesions, blockage, or poor body condition) due directly to plastic ingestion were noted.

Investigation of plastic debris ingestion by four species of sea turtles collected as bycatch in pelagic Pacific longline fisheries.

PubMed

Clukey, Katharine E; Lepczyk, Christopher A; Balazs, George H; Work, Thierry M; Lynch, Jennifer M

2017-07-15

Ingestion of marine debris is an established threat to sea turtles. The amount, type, color and location of ingested plastics in the gastrointestinal tracts of 55 sea turtles from Pacific longline fisheries from 2012 to 2016 were quantified, and compared across species, turtle length, body condition, sex, capture location, season and year. Six approaches for quantifying amounts of ingested plastic strongly correlated with one another and included: number of pieces, mass, volume and surface area of plastics, ratio of plastic mass to body mass, and percentage of the mass of gut contents consisting of plastic. All olive ridley (n=37), 90% of green (n=10), 80% of loggerhead (n=5) and 0% of leatherback (n=3) turtles had ingested plastic; green turtles ingested significantly more than olive ridleys. Most debris was in the large intestines. No adverse health impacts (intestinal lesions, blockage, or poor body condition) due directly to plastic ingestion were noted. Copyright © 2017. Published by Elsevier Ltd.

Do shallow soil, low water availability, or their combination increase the competition between grasses with different root systems in karst soil?

PubMed

Zhao, Yajie; Li, Zhou; Zhang, Jing; Song, Haiyan; Liang, Qianhui; Tao, Jianping; Cornelissen, Johannes H C; Liu, Jinchun

2017-04-01

Uneven soil depth and low water availability are the key limiting factors to vegetation restoration and reconstruction in limestone soils such as in vulnerable karst regions. Belowground competition will possibly increase under limited soil resources. Here, we investigate whether low resource availability (including shallow soil, low water availability, and shallow soil and low water availability combined) stimulates the competition between grasses with different root systems in karst soil, by assessing their growth response, biomass allocation, and morphological plasticity. In a full three-way factorial blocked design of soil depth by water availability by neighbor identity, we grew Festuca arundinacea (deep-rooted) and Lolium perenne (shallow-rooted) under normal versus shallow soil depth, high versus low water availability, and in monoculture (conspecific neighbor) versus mixture (neighbor of the other species). The key results were as follows: (1) total biomass and aboveground biomass in either of the species decreased with reduction of resources but were not affected by planting patterns (monoculture or mixture) even at low resource levels. (2) For F. arundinacea, root biomass, root mass fraction, total root length, and root volume were higher in mixture than in monoculture at high resource level (consistent with resource use complementarity), but lower in mixture than in monoculture at low resource levels (consistent with interspecific competition). In contrast for L. perenne, either at high or low resource level, these root traits had mostly similar values at both planting patterns. These results suggest that deep-rooted and shallow-rooted plant species can coexist in karst regions under current climatic regimes. Declining resources, due to shallow soil, a decrease in precipitation, or combined shallow soil and karst drought, increased the root competition between plants of deep-rooted and shallow-rooted species. The root systems of deep-rooted plants may be too small to get sufficient water and nutrients from dry, shallow soil, while shallow-rooted plants will maintain a dominant position with their already adaptive strategy in respect of root biomass allocation and root growth.

Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chong-Qing; Wang, Hui, E-mail: huiwang1968@163.com; Liu, You-Nian

Highlights: • Factors of NaOH treatment were studied by orthogonal and single factor experiments. • Mechanism of alkaline treatment for facilitating flotation was manifested. • Flotation separation of PET was achieved with high purity and efficiency. • A flow sheet of purification PET from MWP was designed. - Abstract: Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by froth flotation combined with alkalinemore » pretreatment was investigated for recycling industry. The effect of process variables was estimated by L{sub 9} (3{sup 4}) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10 wt% sodium hydroxide, 20 min and 70 °C. After alkaline pretreatment under optimum conditions, flotation separation PET from acrylonitrile–butadiene–styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of froth flotation and sink float separation was designed. This study facilitates industrial application of plastics flotation and provides technical insights into recycling of waste plastics.« less

Defect-induced solid state amorphization of molecular crystals

NASA Astrophysics Data System (ADS)

Lei, Lei; Carvajal, Teresa; Koslowski, Marisol

2012-04-01

We investigate the process of mechanically induced amorphization in small molecule organic crystals under extensive deformation. In this work, we develop a model that describes the amorphization of molecular crystals, in which the plastic response is calculated with a phase field dislocation dynamics theory in four materials: acetaminophen, sucrose, γ-indomethacin, and aspirin. The model is able to predict the fraction of amorphous material generated in single crystals for a given applied stress. Our results show that γ-indomethacin and sucrose demonstrate large volume fractions of amorphous material after sufficient plastic deformation, while smaller amorphous volume fractions are predicted in acetaminophen and aspirin, in agreement with experimental observation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grove, John W.

We investigate sufficient conditions for thermodynamic consistency for equilibrium mixtures. Such models assume that the mass fraction average of the material component equations of state, when closed by a suitable equilibrium condition, provide a composite equation of state for the mixture. Here, we show that the two common equilibrium models of component pressure/temperature equilibrium and volume/temperature equilibrium (Dalton, 1808) define thermodynamically consistent mixture equations of state and that other equilibrium conditions can be thermodynamically consistent provided appropriate values are used for the mixture specific entropy and pressure.

Production, characterization and fuel properties of alternative diesel fuel from pyrolysis of waste plastic grocery bags

USDA-ARS?s Scientific Manuscript database

Pyrolysis of HDPE waste grocery bags followed by distillation resulted in a liquid hydrocarbon mixture that consisted of saturated aliphatic paraffins (96.8%), aliphatic olefins (2.6%), and aromatics (0.6%) that corresponded to the boiling range of conventional petroleum diesel fuel (#1 diesel 182–2...

PVC removal from mixed plastics by triboelectrostatic separation.

PubMed

Park, Chul-Hyun; Jeon, Ho-Seok; Park, Jai-Koo

2007-06-01

Ever increasing oil price and the constant growth in generation of waste plastics stimulate a research on material separation for recycling of waste plastics. At present, most waste plastics cause serious environmental problems due to the disposal by reclamation and incineration. Particularly, polyvinyl chloride (PVC) materials among waste plastics generates hazardous HCl gas, dioxins containing Cl, and so on, which lead to air pollution and shorten the life of incinerator, and it makes difficultly recycling of other plastics. Therefore, we designed a bench scale triboelectrostatic separator for PVC removal from mixed plastics (polyvinyl chloride/polyethylene terephthalate), and then carried out material separation tests. In triboelectrostatic separation, PVC and PET particles are charged negatively and positively, respectively, due to the difference of the work function of plastics in tribo charger of the fluidized-bed, and are separated by means of splitter through an opposite electric field. In this study, the charge efficiency of PVC and PET was strongly dependent on the tribo charger material (polypropylene), relative humidity (below 30%), air velocity (over 10 m/s), and mixture ratio (PET:PVC=1:1). At the optimum conditions (electrode potential of 20 kV and splitter position of -2 cm), PVC rejection and PET recovery in PET products were 99.60 and 98.10%, respectively, and the reproducibility of optimal test was very good (+/-1%). In addition, as a change of splitter position, we developed the technique to recover high purity PET (over 99.99%) although PET recovery decreases by degrees.

Recycled tires as coarse aggregate in concrete pavement mixtures.

DOT National Transportation Integrated Search

2013-07-01

The reuse potential of tire chips as coarse aggregates in pavement concrete was examined in this research by : investigating the effects of low- and high-volume tire chips on fresh and hardened concrete properties. One concrete : control mixture was ...

Composite materials for thermal energy storage

NASA Astrophysics Data System (ADS)

Benson, D. K.; Burrows, R. W.; Shinton, Y. D.

1985-01-01

A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations are discussed. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

Composite materials for thermal energy storage

DOEpatents

Benson, David K.; Burrows, Richard W.; Shinton, Yvonne D.

1986-01-01

The present invention discloses composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These phase change materials do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions, such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

Composite materials for thermal energy storage

DOEpatents

Benson, D.K.; Burrows, R.W.; Shinton, Y.D.

1985-01-04

A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

Asphalt dust waste material as a paste volume in developing sustainable self compacting concrete (SCC)

NASA Astrophysics Data System (ADS)

Ismail, Isham; Shahidan, Shahiron; Bahari, Nur Amira Afiza Saiful

2017-12-01

Self-compacting concrete (SCC) mixtures are usually designed to have high workability during the fresh state through the influence of higher volumes of paste in concrete mixtures. Asphalt dust waste (ADW) is one of disposed materials obtained during the production of asphalt premix. These fine powder wastes contribute to environmental problems today. However, these waste materials can be utilized in the development of sustainable and economical SCC. This paper focuses on the preliminary evaluations of the fresh properties and compressive strength of developed SCC for 7 and 28 days only. 144 cube samples from 24 mixtures with varying water binder ratios (0.2, 0.3 and 0.4) and ADW volume (0% to 100%) were prepared. MD940 and MD950 showed a satisfactory performance for the slump flow, J-Ring, L-Box and V-Funnel tests at fresh state. The compressive strength after 28 days for MD940 and MD950 was 36.9 MPa and 28.0 MPa respectively. In conclusion, the use of ADW as paste volume should be limited and a higher water binder ratio will significantly reduce the compressive strength.

Effects of concentration, temperature and solvent composition on density and apparent molar volume of the binary mixtures of cationic-anionic surfactants in methanol-water mixed solvent media.

PubMed

Bhattarai, Ajaya; Chatterjee, Sujeet Kumar; Niraula, Tulasi Prasad

2013-01-01

The accurate measurements on density of the binary mixtures of cetyltrimethylammonium bromide and sodium dodecyl sulphate in pure water and in methanol(1) + water (2) mixed solvent media containing (0.10, 0.20, and 0.30) volume fractions of methanol at 308.15, 318.15, and 323.15 K are reported. The concentrations are varied from (0.03 to 0.12) mol.l(-1) of sodium dodecyl sulphate in presence of ~ 5.0×10(-4) mol.l(-1) cetyltrimethylammonium bromide. The results showed almost increase in the densities with increasing surfactant mixture concentration, also the densities are found to decrease with increasing temperature over the entire concentration range, investigated in a given mixed solvent medium and these values are found to decrease with increasing methanol content in the solvent composition. The concentration dependence of the apparent molar volumes appear to be negligible over the entire concentration range, investigated in a given mixed solvent medium and the apparent molar volumes increase with increasing temperature and are found to decrease with increasing methanol content in the solvent composition.

Sugar maple sap volume increases as vacuum level is increased

Treesearch

Russell S. Walters; H. Clay Smith

1975-01-01

Maple sap yields collected by using plastic tubing with a vacuum pump increased as the vacuum level was increased. Sap volumes collected at the 10- and 15-inch mercury vacuum levels were statistically significantly higher than volumes collected at the 5-inch level. Although the 15-inch vacuum yielded more sap than the 10-inch vacuum, the difference was not...

EDCs Mixtures: A Stealthy Hazard for Human Health?

PubMed

Ribeiro, Edna; Ladeira, Carina; Viegas, Susana

2017-02-07

Endocrine disrupting chemicals (EDCs) are exogenous chemicals that may occur naturally (e.g., phytoestrogens), while others are industrial substances and plasticizers commonly utilized worldwide to which human exposure, particularly at low-doses, is omnipresent, persistent and occurs in complex mixtures. EDCs can interfere with/or mimic estrogenic hormones and, consequently, can simultaneously trigger diverse signaling pathways which result in diverse and divergent biological responses. Additionally, EDCs can also bioaccumulate in lipid compartments of the organism forming a mixed "body burden" of contaminants. Although the independent action of chemicals has been considered the main principle in EDCs mixture toxicity, recent studies have demonstrated that numerous effects cannot be predicted when analyzing single compounds independently. Co-exposure to these agents, particularly in critical windows of exposure, may induce hazardous health effects potentially associated with a complex "body burden" of different origins. Here, we performed an exhaustive review of the available literature regarding EDCs mixtures exposure, toxicity mechanisms and effects, particularly at the most vulnerable human life stages. Although the assessment of potential risks to human health due to exposure to EDCs mixtures is a major topic for consumer safety, information regarding effective mixtures effects is still scarce.

Mixtures of Chemical Pollutants at European Legislation Safety Concentrations: How Safe Are They?

PubMed Central

Carvalho, Raquel N.; Arukwe, Augustine; Ait-Aissa, Selim; Bado-Nilles, Anne; Balzamo, Stefania; Baun, Anders; Belkin, Shimshon; Blaha, Ludek; Brion, François; Conti, Daniela; Creusot, Nicolas; Essig, Yona; Ferrero, Valentina E. V.; Flander-Putrle, Vesna; Fürhacker, Maria; Grillari-Voglauer, Regina; Hogstrand, Christer; Jonáš, Adam; Kharlyngdoh, Joubert B.; Loos, Robert; Lundebye, Anne-Katrine; Modig, Carina; Olsson, Per-Erik; Pillai, Smitha; Polak, Natasa; Potalivo, Monica; Sanchez, Wilfried; Schifferli, Andrea; Schirmer, Kristin; Sforzini, Susanna; Stürzenbaum, Stephen R.; Søfteland, Liv; Turk, Valentina; Viarengo, Aldo; Werner, Inge; Yagur-Kroll, Sharon; Zounková, Radka; Lettieri, Teresa

2014-01-01

The risk posed by complex chemical mixtures in the environment to wildlife and humans is increasingly debated, but has been rarely tested under environmentally relevant scenarios. To address this issue, two mixtures of 14 or 19 substances of concern (pesticides, pharmaceuticals, heavy metals, polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic levels. A consortium of 16 laboratories was involved in performing the bioassays. The mixtures elicited quantifiable toxic effects on some of the test systems employed, including i) changes in marine microbial composition, ii) microalgae toxicity, iii) immobilization in the crustacean Daphnia magna, iv) fish embryo toxicity, v) impaired frog embryo development, and vi) increased expression on oxidative stress-linked reporter genes. Estrogenic activity close to regulatory safety limit concentrations was uncovered by receptor-binding assays. The results highlight the need of precautionary actions on the assessment of chemical mixtures even in cases where individual toxicants are present at seemingly harmless concentrations. PMID:24958932

EDCs Mixtures: A Stealthy Hazard for Human Health?

PubMed Central

Ribeiro, Edna; Ladeira, Carina; Viegas, Susana

2017-01-01

Endocrine disrupting chemicals (EDCs) are exogenous chemicals that may occur naturally (e.g., phytoestrogens), while others are industrial substances and plasticizers commonly utilized worldwide to which human exposure, particularly at low-doses, is omnipresent, persistent and occurs in complex mixtures. EDCs can interfere with/or mimic estrogenic hormones and, consequently, can simultaneously trigger diverse signaling pathways which result in diverse and divergent biological responses. Additionally, EDCs can also bioaccumulate in lipid compartments of the organism forming a mixed “body burden” of contaminants. Although the independent action of chemicals has been considered the main principle in EDCs mixture toxicity, recent studies have demonstrated that numerous effects cannot be predicted when analyzing single compounds independently. Co-exposure to these agents, particularly in critical windows of exposure, may induce hazardous health effects potentially associated with a complex “body burden” of different origins. Here, we performed an exhaustive review of the available literature regarding EDCs mixtures exposure, toxicity mechanisms and effects, particularly at the most vulnerable human life stages. Although the assessment of potential risks to human health due to exposure to EDCs mixtures is a major topic for consumer safety, information regarding effective mixtures effects is still scarce. PMID:29051438

Apparent diffusion coefficient of hyperpolarized (3)He with minimal influence of the residual gas in small animals.

PubMed

Carrero-González, L; Kaulisch, T; Ruiz-Cabello, J; Pérez-Sánchez, J M; Peces-Barba, G; Stiller, D; Rodríguez, I

2012-09-01

The apparent diffusion coefficient (ADC) of hyperpolarized (HP) gases is a parameter that reflects changes in lung microstructure. However, ADC is dependent on many physiological and experimental variables that need to be controlled or specified in order to ensure the reliability and reproducibility of this parameter. A single breath-hold experiment is desirable in order to reduce the amount of consumed HP gas. The application of a positive end-expiratory pressure (PEEP) causes an increase in the residual gas volume. Depending on the applied PEEP, the ratio between the incoming and residual gas volumes will change and the ADC will vary, as long as both gases do not have the same diffusion coefficient. The most standard method for human applications uses air for breathing and a bolus of pure HP (3)He for MRI data acquisition. By applying this method in rats, we have demonstrated that ADC values are strongly dependent on the applied PEEP, and therefore on the residual gas volume in the lung. This outcome will play an important role in studies concerning certain diseases, such as emphysema, which is characterized by an increase in the residual volume. Ventilation with an oxygen-helium mixture (VOHeM) is a proposed single breath-hold method that uses two different gas mixtures (O(2)-(4)He for ventilation and HP (3)He-N(2) for imaging). The concentration of each gas in its respective mixture was calculated in order to obtain the same diffusion coefficient in both mixtures. ADCs obtained from VOHeM are independent of PEEP, thus minimizing the effect of the different residual volumes. Copyright © 2012 John Wiley & Sons, Ltd.

Imaging Effects of Neurotrophic Factor Genes on Brain Plasticity and Repair in Multiple Sclerosis

DTIC Science & Technology

2010-07-01

cortical thickness and subcortical volume measures, lesion volumetry , and voxel-based morphometry and diffusion imaging. We are continuing to...th ickness and subcortical volume measures, lesion volumetry , and voxel-based morphometry and diffusion imaging. Regressio n and symbolic modeling

Stability of an extemporaneously prepared thalidomide suspension.

PubMed

Kraft, Shawna; Johnson, Cary E; Tyler, Ryan P

2012-01-01

The short-term physical and chemical stability of an oral suspension of thalidomide 20 mg/mL was studied. An oral suspension of thalidomide 20 mg/mL was prepared by emptying the contents of 12 100-mg thalidomide capsules into a glass mortar; 30 mL of Ora-Plus and 30 mL of Ora-Sweet were mixed and added to the thalidomide powder to make a final volume of 60 mL. Three identical samples of the formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and stored under refrigeration (3-5 °C). A 1-mL sample was withdrawn from each of the three samples with a micropipette immediately after preparation and at 7, 14, 21, 28, and 35 days. After further dilution to an expected concentration of 20 μg/mL with acetonitrile-methanol and then dilution with mobile phase, the samples were assayed in duplicate using stability-indicating high-performance liquid chromatography. Stability was determined by evaluating the percentage of the initial concentration remaining at each time point; stability was defined as the retention of at least 90% of the initial concentration of thalidomide. At least 92% of the initial thalidomide concentration remained throughout the 35-day study period. There were no detectable changes in color, odor, or pH and no visible microbial growth in any sample. An extemporaneously prepared suspension of thalidomide 20 mg/mL in a 1:1 mixture of Ora-Plus and Ora-Sweet was stable for at least 35 days when stored in 2-oz amber plastic bottles under refrigeration.

Biodegradation of compostable and oxodegradable plastic films by backyard composting and bioaugmentation.

PubMed

Quecholac-Piña, Xochitl; García-Rivera, Mariel Anel; Espinosa-Valdemar, Rosa María; Vázquez-Morillas, Alethia; Beltrán-Villavicencio, Margarita; Cisneros-Ramos, Adriana de la Luz

2017-11-01

Plastics are widely used in the production of short-life products, which are discarded producing an accumulation of these materials and problems due to their persistence in the environment and waste management systems. Degradable plastics (compostable, oxodegradable) have been presented as an alternative to decrease the negative effect of plastic waste. In this research, the feasibility of degrading a commercially available compostable film and oxodegradable polyethylene, with and without previous abiotic oxidation, is assessed in a home composting system. Reactors (200 L) were used to degrade the plastic films along with a mixture of organic food waste (50 %), mulch (25 %), and dry leaves (25 %), amended with yeast and a solution of brown sugar to increase the speed of the process. The presence of the plastic film did not affect the composting process, which showed an initial increase in temperature and typical profiles for moisture content, pH, with a final C/N of 17.4. After 57 days, the compostable plastic has decreased its mechanical properties in more than 90 %, while the oxodegradable film did not show significant degradation if it was not previously degraded by UV radiation. The use of these plastics should be assessed against the prevailing waste management system in each city or country. In the case of Mexico, which lacks the infrastructure for industrial composting, home composting could be an option to degrade compostable plastics along organic waste. However, more testing is needed in order to set the optimal parameters of the process.

Development and evaluation of Pleurotus tuber-regium-cornstarch composite as a direct compression multifunctional excipient.

PubMed

Okoye, Ebere I; Onyekweli, Anthony O

2016-01-01

The aim was to develop a novel excipient from Pleurotus tuber-regium (PT)-cornstarch (CS) mixture and evaluate its multifunctional characteristics in tablet formulation. Composites were generated from dephytochemicalized PT and CS combined at 1:1 to 4:1 ratios and pregelatinized in a hot water bath at 65°C ± 2°C for 5 min. The paste was dried, pulverized, and screened through 150-μm sieve. PT-CS physical mixtures were prepared and their characteristics/functionalities in tableting chloroquine were compared to those of composites and microcrystalline cellulose (Avicel(®)). PT ash value was 0.40 ± 0.09% and heavy metal contents were below official limits. PT's differential scanning calorimetric (DSC) thermogram depicted broad melting peak at 329.5°C; this peak was attenuated by the presence of CS. Fourier transform infrared (FTIR) spectra predicted compatibility between PT and CS. Composites consolidated better and also flowed better than physical mixtures and Avicel(®). Increasing PT content enhanced the excipients' swellabilities, and composites possessed significantly (P < 0.05) better swelling indices than Avicel(®). The composites underwent fragmentation before plastic deformation with yield pressures significantly (P < 0.05) higher than those of the physical mixtures, which exhibited only plastic deformation. The mechanical properties of chloroquine tablets were acceptable, with the 1:4 (PT:CS) imparting the best properties. Mean disintegration times for the commercial comparator and Avicel(®) -containing tablets were significantly higher (P < 0.05) than those of composites. Drug release from tablets formulated with composites were similar to the commercial comparator, but significantly higher (P < 0.05) than those of Avicel(®). The novel composites are excellent multifunctional excipients, the best (PT:CS 1:4) one showcasing potentially better mechanical functionality than Avicel(®), a popular multifunctional excipient.

Chemical compatibility screening test results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nigrey, P.J.; Dickens, T.G.

1997-12-01

A program for evaluating packaging components that may be used in transporting mixed-waste forms has been developed and the first phase has been completed. This effort involved the screening of ten plastic materials in four simulant mixed-waste types. These plastics were butadiene-acrylonitrile copolymer rubber, cross-linked polyethylene (XLPE), epichlorohydrin rubber, ethylene-propylene rubber (EPDM), fluorocarbon (Viton or Kel-F), polytetrafluoroethylene, high-density polyethylene (HDPE), isobutylene-isoprene copolymer rubber (butyl), polypropylene, and styrene-butadiene rubber (SBR). The selected simulant mixed wastes were (1) an aqueous alkaline mixture of sodium nitrate and sodium nitrite; (2) a chlorinated hydrocarbon mixture; (3) a simulant liquid scintillation fluid; and (4) amore » mixture of ketones. The testing protocol involved exposing the respective materials to 286,000 rads of gamma radiation followed by 14-day exposures to the waste types at 60{degrees}C. The seal materials were tested using vapor transport rate (VTR) measurements while the liner materials were tested using specific gravity as a metric. For these tests, a screening criterion of 0.9 g/hr/m{sup 2} for VTR and a specific gravity change of 10% was used. Based on this work, it was concluded that while all seal materials passed exposure to the aqueous simulant mixed waste, EPDM and SBR had the lowest VTRs. In the chlorinated hydrocarbon simulant mixed waste, only Viton passed the screening tests. In both the simulant scintillation fluid mixed waste and the ketone mixture simulant mixed waste, none of the seal materials met the screening criteria. For specific gravity testing of liner materials, the data showed that while all materials with the exception of polypropylene passed the screening criteria, Kel-F, HDPE, and XLPE offered the greatest resistance to the combination of radiation and chemicals.« less

The valorization of the plastic waste to the rheological characteristics of bituminous mixtures

NASA Astrophysics Data System (ADS)

Boucherba, Mohammed; Kriker, Abdelouahed; Kebaili, Nabil

2017-02-01

The valorization of materials used at the end of the cycle currently constitutes one of the major challenges for the state for the safeguarding of the environment. Indeed, plastic waste from their obstruction and weak biodegradability often constitutes a threat for health, nature and the environment. The present study treats a mining method and valorization of these wastes in the road, where this waste is incorporated in the pure bitumen of asphalt concretes using the Dry process. The vital objective of this work is to see their impact on the mechanical behavior of these concretes using the Marshall Test and NAT.

Photoperiodic differences in a forebrain nucleus involved in vocal plasticity: enkephalin immunoreactivity reveals volumetric variation in song nucleus lMAN but not NIf in male European starlings (Sturnus vulgaris)

PubMed Central

Stevenson, Tyler J; Ball, Gregory F

2010-01-01

Seasonal variation in the volume of various song control nuclei in many passerine species remains one of the best examples of naturally occurring adult neuroplasticity among vertebrates. The lateral portion of the magnocellular nucleus of the anterior nidopallium (lMAN) is a song nucleus that is important for song learning and seems to be critical for inducing variability in the song structure that is later pruned via a feedback process to produce adult crystallized song. To date, lMAN has not been shown to exhibit seasonal changes in volume, probably because it is difficult to resolve the boundaries of lMAN when employing histological methods based on Nissl staining. Here, lMANcore volumes were examined in intact photostimulated (i.e. breeding), castrated photostimulated and photorefractory (i.e. non-breeding) male starlings (Sturnus vulgaris) to investigate the degree of seasonal variation in brain morphology. We present data demonstrating that the volumes of the total MAN and lMANcore delineated by enkephalin immunoreactivity are greater in photostimulated male starlings as compared to photorefractory males. Moreover, two other regions associated with the song system that have not been investigated previously in the context of seasonal plasticity namely i) the medial portion of MAN (mMAN), and ii) the nucleus interfacialis (NIf) did not display significant volumetric variation. We propose that greater lMANcore volumes are associated with the increase in vocal plasticity which is generally observed prior to production of stereotyped song. PMID:20556824

Photoperiodic differences in a forebrain nucleus involved in vocal plasticity: enkephalin immunoreactivity reveals volumetric variation in song nucleus lMAN but not NIf in male European starlings (Sturnus vulgaris).

PubMed

Stevenson, Tyler J; Ball, Gregory F

2010-09-15

Seasonal variation in the volume of various song control nuclei in many passerine species remains one of the best examples of naturally occurring adult neuroplasticity among vertebrates. The lateral portion of the magnocellular nucleus of the anterior nidopallium (lMAN) is a song nucleus that is important for song learning and seems to be critical for inducing variability in the song structure that is later pruned via a feedback process to produce adult crystallized song. To date, lMAN has not been shown to exhibit seasonal changes in volume, probably because it is difficult to resolve the boundaries of lMAN when employing histological methods based on Nissl staining. Here, lMAN(core) volumes were examined in intact photostimulated (i.e., breeding), castrated photostimulated and photorefractory (i.e., nonbreeding) male starlings (Sturnus vulgaris) to investigate the degree of seasonal variation in brain morphology. We present data demonstrating that the volumes of the total MAN and lMAN(core) delineated by enkephalin immunoreactivity are greater in photostimulated male starlings as compared to photorefractory males. Moreover, two other regions associated with the song system that have not been investigated previously in the context of seasonal plasticity namely (i) the medial portion of MAN (mMAN), and (ii) the nucleus interfacialis (NIf) did not display significant volumetric variation. We propose that greater lMAN(core) volumes are associated with the increase in vocal plasticity that is generally observed prior to production of stereotyped song.

Measurement of Workability of Fresh Concrete Using a Mixing Truck

PubMed Central

Amziane, Sofiane; Ferraris, Chiara F.; Koehler, Eric P.

2005-01-01

The main objective of this study is to evaluate the workability of fresh portland cement concrete while it is still in the mixing truck by determining fundamental rheological parameters (plastic viscosity and yield stress). Nine concrete mixtures with different values of yield stress and plastic viscosity were tested in a concrete truck. The measurements made with the truck were based on the typical method of determining the flow behavior in a traditional fluid rheometer; that is, the shear rate in the mixing truck was swept from high to low by varying the rotation speed of the drum. The results of these experiments are discussed and compared with data provided by the ICAR rheometer, a portable rheometer designed for measuring concrete rheology. The test results indicate that the mixing truck equipment is sufficiently sensitive to detect differences in yield stress, slump, and plastic viscosity. However, the plastic viscosity determined by the truck measurement did not correlate with plastic viscosity as measured by the ICAR rheometer, while the yield stress determined by the truck measurement did correlate well with the measured slump and the ICAR rheometer results Suggestions are given on how to improve the mixing truck for better use as a rheometer. PMID:27308103

Lattice model for water-solute mixtures.

PubMed

Furlan, A P; Almarza, N G; Barbosa, M C

2016-10-14

A lattice model for the study of mixtures of associating liquids is proposed. Solvent and solute are modeled by adapting the associating lattice gas (ALG) model. The nature of interaction of solute/solvent is controlled by tuning the energy interactions between the patches of ALG model. We have studied three set of parameters, resulting in, hydrophilic, inert, and hydrophobic interactions. Extensive Monte Carlo simulations were carried out, and the behavior of pure components and the excess properties of the mixtures have been studied. The pure components, water (solvent) and solute, have quite similar phase diagrams, presenting gas, low density liquid, and high density liquid phases. In the case of solute, the regions of coexistence are substantially reduced when compared with both the water and the standard ALG models. A numerical procedure has been developed in order to attain series of results at constant pressure from simulations of the lattice gas model in the grand canonical ensemble. The excess properties of the mixtures, volume and enthalpy as the function of the solute fraction, have been studied for different interaction parameters of the model. Our model is able to reproduce qualitatively well the excess volume and enthalpy for different aqueous solutions. For the hydrophilic case, we show that the model is able to reproduce the excess volume and enthalpy of mixtures of small alcohols and amines. The inert case reproduces the behavior of large alcohols such as propanol, butanol, and pentanol. For the last case (hydrophobic), the excess properties reproduce the behavior of ionic liquids in aqueous solution.

Plastic in the Thames: a river runs through it.

PubMed

Morritt, David; Stefanoudis, Paris V; Pearce, Dave; Crimmen, Oliver A; Clark, Paul F

2014-01-15

Although contamination of the marine ecosystems by plastics is becoming recognised as a serious pollution problem, there are few studies that demonstrate the contribution made by freshwater catchments. Over a three month period from September to December 2012, at seven localities in the upper Thames estuary, 8490 submerged plastic items were intercepted in eel fyke nets anchored to the river bed. Whilst there were significant differences in the numbers of items at these locations, the majority were some type of plastic. Additionally in excess of 20% of the litter items were components of sanitary products. The most contaminated sites were in the vicinity of sewage treatment works. While floating litter is visible, this study also demonstrates that a large unseen volume of submerged plastic is flowing into the marine environment. It is therefore important that this sub-surface component is considered when assessing plastic pollution input into the sea. Copyright © 2013 Elsevier Ltd. All rights reserved.

Determinants of recycling common types of plastic product waste in environmental horticulture industry: The case of Georgia.

PubMed

Meng, Ting; Klepacka, Anna M; Florkowski, Wojciech J; Braman, Kristine

2016-02-01

Environmental horticulture firms provide a variety of commercial/residential landscape products and services encompassing ornamental plant production, design, installation, and maintenance. The companies generate tons of waste including plastic containers, trays, and greenhouse/field covers, creating the need to reduce and utilize plastic waste. Based on survey data collected in Georgia in 2013, this paper investigates determinants of the environmental horticulture firms' recycling decision (plastic containers, flats, and greenhouse poly). Our findings indicate that the decision to discard vs. recycle plastic containers, flats, and greenhouse poly is significantly influenced by firm scope, size, location, and partnership with recycling providers, as well as whether recycling providers offer additional waste pickup services. Insights from this study are of use to local governments and environmental organizations interested in increasing horticultural firm participation in recycling programs and lowering the volume of plastic destined for landfills. Copyright © 2015 Elsevier Ltd. All rights reserved.

Imaging Effects of Neurotrophic Factor Genes on Brain Plasticity and Repair in Multiple Sclerosis

DTIC Science & Technology

2011-07-01

focal and diffuse effects in brain (including cortical thickness and subcortical volume measures, lesion volumetry , and voxel-based morphometry and...to both focal and diffuse effects in gray and white matter, including cortical thickness and subcortical volume measures, lesion volumetry , and

State relations for a two-phase mixture of reacting explosives and applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubota, Shiro; Saburi, Tei; Ogata, Yuji

2007-10-15

To assess the assumptions behind the two phase mixture rule for reacting explosives, the shock-to-detonation transition process was calculated for high explosives using a finite difference method. An ignition and growth model and the Jones-Wilkins-Lee (JWL) equations of state were employed. The simple mixture rule assumes that the reacting explosive is a simple mixture of the reactant and product components. Four different assumptions, such as that of thermal equilibrium and isotropy, were adopted to calculate the pressure. The main purpose of this paper is to present the answer to the question of why the numerical results of shock-initiation are insensitivemore » to the assumptions adopted. The equations of state for reactants and products were assessed by considering plots of the specific internal energy E and specific volume V. If the slopes of the constant-pressure lines for both components in the E-V plane are almost the same, it is demonstrated that the numerical results are insensitive to the assumptions adopted. We have found that the relation for the specific volumes of the two components can be approximately expressed by a single curve of the specific volume of the reactant vs that of the products. We discuss this relationship in terms of the results of the numerical simulation. (author)« less

Certification Examination Cases of Candidates for Certification by the American Board of Plastic Surgery: Trends in Practice Profiles Spanning a Decade (2000–2009)

PubMed Central

Chung, Kevin C.; Song, Jae W.; Shauver, Melissa J.; Cullison, Terry M.; Noone, R. Barrett

2011-01-01

Background To evaluate the case mix of plastic surgeons in their early years of practice by examining candidate case-logs submitted for the Oral Examination. Methods De-identified data from 2000–2009 consisting of case-logs submitted by young plastic surgery candidates for the Oral Examination were analyzed. Data consisted of exam year, CPT (Current Procedural Terminology) Codes and the designation of each CPT code as cosmetic or reconstructive by the candidate, and patient age and gender. Subgroup analyses for comprehensive, cosmetic, craniomaxillofacial, and hand surgery modules were performed by using the CPT code list designated by the American Board of Plastic Surgery Maintenance of Certification in Plastic Surgery ( ) module framework. Results We examined case-logs from a yearly average of 261 candidates over 10 years. Wider variations in yearly percent change in median cosmetic surgery case volumes (−62.5% to 30%) were observed when compared to the reconstructive surgery case volumes (−18.0% to 25.7%). Compared to cosmetic surgery cases per candidate, which varied significantly from year-to-year (p<0.0001), reconstructive surgery cases per candidate did not vary significantly (p=0.954). Subgroup analyses of proportions of types of surgical procedures based on CPT code categories, revealed hand surgery to be the least performed procedure relative to comprehensive, craniomaxillofacial, and cosmetic surgery procedures. Conclusions Graduates of plastic surgery training programs are committed to performing a broad spectrum of reconstructive and cosmetic surgical procedures in their first year of practice. However, hand surgery continues to have a small presence in the practice profiles of young plastic surgeons. PMID:21788850

Whole-Volume Clustering of Time Series Data from Zebrafish Brain Calcium Images via Mixture Modeling.

PubMed

Nguyen, Hien D; Ullmann, Jeremy F P; McLachlan, Geoffrey J; Voleti, Venkatakaushik; Li, Wenze; Hillman, Elizabeth M C; Reutens, David C; Janke, Andrew L

2018-02-01

Calcium is a ubiquitous messenger in neural signaling events. An increasing number of techniques are enabling visualization of neurological activity in animal models via luminescent proteins that bind to calcium ions. These techniques generate large volumes of spatially correlated time series. A model-based functional data analysis methodology via Gaussian mixtures is suggested for the clustering of data from such visualizations is proposed. The methodology is theoretically justified and a computationally efficient approach to estimation is suggested. An example analysis of a zebrafish imaging experiment is presented.

On the description of the turbulent flame acceleration with Kolmogorov law

NASA Astrophysics Data System (ADS)

Golub, V. V.; Volodin, V. V.

2018-01-01

A series of experiments on the flame propagation in a hydrogen-air mixtures in a cylindrical envelope of 4.5 m3 volume were carried out. Flame front propagation was recorded using ionization probes and video in the visible and infrared ranges. The flame propagation data interpretation using the Kolmogorov law has been applied. For the first time variation of turbulent energy dissipation rate per weight with combustion propagation was used. This approach allows the experimental data for mixtures with different compositions in non-spherical volumes to be described.

The influence of calcium nitrate on setting and hardening rate of Portland cement concrete at different temperatures

NASA Astrophysics Data System (ADS)

Kičaitė, A.; Pundienė, I.; Skripkiūnas, G.

2017-10-01

Calcium nitrate in mortars and concrete is used as a multifunctional additive: as set accelerator, plasticizer, long term strength enhancer and as antifreeze admixture. Used binding material and the amount of calcium nitrate, affect the characteristics of the concrete mixture and strength of hardened concrete. The setting time of the initial and the final binding at different temperatures of hardening (+ 20 °C and + 5 °C) of the pastes made of different cements (Portland cement CEM I 42.5 R and Portland limestone cement CEM II/A-LL 42.5 R) and various amounts of calcium nitrate from 1 % until 3 % were investigated. The effect of calcium nitrate on technological characteristics of concrete mixture (the consistency of the mixture, the density, and the amount of air in the mixture), on early concrete strength after 2 and 7 days, as well as on standard concrete strength after 28 days at different temperatures (at + 20 °C and + 5 °C) were analysed.

New plastic recycling technology | Science Inventory | US EPA

EPA Pesticide Factsheets

Greater than 60% of the total plastic content of municipal solid waste is comprised of polyolefins (high-density, low-density, and linear polyethylene and polypropylene. Polyethylene (PE) is the largest-volume component but presents a challenge due to the absence of low-energy degradation processes. This news column provides a digest of recent technical reports relating to clean technology and environmental policy,

Laboratory and environmental decay of wood–plastic composite boards: flexural properties

Treesearch

Rebecca Ibach; Marek Gnatowski; Grace Sun; Jessie Glaeser; Mathew Leung; John Haight

2017-01-01

The flexural properties of wood–plastic composite (WPC) deck boards exposed to 9.5 years of environmental decay in Hilo, Hawaii, were compared to samples exposed to moisture and decay fungi for 12 weeks in the laboratory, to establish a correlation between sample flexural properties and calculated void volume. Specimens were tested for flexural strength and modulus,...

Study on Solution Properties of Binary Mixtures of Some Industrially Important Solvents with Cyclohexylamine and Cyclohexanone at 298.15 K

NASA Astrophysics Data System (ADS)

Roy, Mahendra Nath; Das, Rajesh Kumar; Chanda, Riju

2010-03-01

Densities and viscosities were measured for the binary mixtures of cyclohexylamine and cyclohexanone with butyl acetate, butanone, butylamine, tert-butylamine, and 2-butoxyethanol at 298.15 K over the entire composition range. From density data, the values of the excess molar volume ( V E) have been calculated. The experimental viscosity data were correlated by means of the equation of Grunberg-Nissan. The density and viscosity data have been analyzed in terms of some semiempirical viscosity models. The results are discussed in terms of molecular interactions and structural effects. The excess molar volume is found to be either negative or positive depending on the molecular interactions and the nature of the liquid mixtures and is discussed in terms of molecular interactions and structural changes.

40 CFR 799.5085 - Chemical testing requirements for certain high production volume chemicals.

Code of Federal Regulations, 2011 CFR

2011-07-01

... diluted in water or tested as a stabilized mixture with an appropriate stabilizer (e.g., D-lactose monohydrate is the stabilizer in PETN, NF which is a mixture of 20% by weight PETN and 80% by weight D-lactose...

Carbon Deposition Model for Oxygen-Hydrocarbon Combustion, Volume 2

NASA Technical Reports Server (NTRS)

Hernandez, R.; Ito, J. I.; Niiya, K. Y.

1987-01-01

Presented are details of the design, fabrication, and testing of subscale hardware used in the evaluation of carbon deposition characteristics of liquid oxygen and three hydrocarbon fuels for both main chamber and preburner/gas generator operating conditions. In main chamber conditions, the deposition of carbon on the combustion chamber wall was investigated at mixture ratios of 2.0 to 4.0 and at chamber pressures of 1000 to 1500 psia. No carbon deposition on chamber walls was detected at these main chamber mixture ratios. In preburner/gas generator operating conditions, the deposition of carbon on the turbine simulator tubes was evaluated at mixture ratios of 0.20 to 0.60 and at chamber pressures of 720 to 1650 psia. The results of the tests showed carbon deposition rate to be a strong function of mixture ratio and a weak function of chamber pressure. Further analyses evaluated the operational concequences of carbon deposition on preburner/gas generator performance. This is Volume 2 of the report, which contains data plots of all the test programs.

[Analysis of phthalates in plastic food-packaging bags by thin layer chromatography].

PubMed

Chen, Hui; Wang, Yuan; Zhu, Ruohua

2006-01-01

The method for simultaneous determination of four phthalates, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) in plastic food-packaging bags by thin layer chromatography (TLC) was developed. The plastic food-packaging bags were extracted with ethanol by ultrasonication, then the mixture was filtrated through membrane (0.45 microm). The mixture of ethyl acetate-anhydrous ether-isooctane (1 : 4 : 15, v/v) was used as developing agent on the TLC silica gel plate for development. The filtered liquid was spotted on the TLC plate dealt by acetone, and detected with scanning wavelength of 275 nm and reference wavelength of 340 nm. The qualitative analysis of the phthalates was performed using the R(f) values of the chromatogram. The quantitative analysis was performed with external standard method. Good linearities were obtained for DMP, DEP, DBP and DEHP. The detection limits were 2.1 ng for DMP, 2.4 ng for DEP, 3.4 ng for DBP and 4.0 ng for DEHP. The relative standard deviations (RSDs) of the four phthalates were 2.8% - 3.5%. The recoveries of the four phthalate standards in real sample were 78.58% - 111.04%. The method presented has the advantages of high precision, high sensitivity, small sample size, and simple pretreatment . The method was used to detect the four phthalates in the food-packaging bags. The contents in real samples were close to the results by gas chromatography.

Dynamics in the Plastic Crystalline Phases of Cyclohexanol and Cyclooctanol Studied by Quasielastic Neutron Scattering.

PubMed

Novak, E; Jalarvo, N; Gupta, S; Hong, K; Förster, S; Egami, T; Ohl, M

2018-06-01

Plastic crystals are a promising candidate for solid state ionic conductors. In this work, quasielastic neutron scattering is employed to investigate the center of mass diffusive motions in two types of plastic crystalline cyclic alcohols: cyclohexanol and cyclooctanol. Two separate motions are observed which are attributed to long-range translational diffusion (α-process) and cage rattling (fast β-process). Residence times and diffusion coefficients are calculated for both processes, along with the confinement distances for the cage rattling. In addition, a binary mixture of these two materials is measured to understand how the dynamics change when a second type of molecule is added to the matrix. It is observed that, upon the addition of the larger cyclooctanol molecules into the cyclohexanol solution, the cage size decreases, which causes a decrease in the observed diffusion rates for both the α- and fast β-processes.

California Bearing Ratio (CBR) test on stabilization of clay with lime addition

NASA Astrophysics Data System (ADS)

Hastuty, I. P.; Roesyanto; Limbong, M. N.; Oberlyn, S. J.

2018-02-01

Clay is a type of soil with particles of certain minerals giving plastic properties when mixed with water. Soil has an important role in a construction, besides as a building material in a wide variety of civil engineering works, soil is also used as supporting foundation of the building. Basic properties of clay are rock-solid in dry and plastic with medium water content. In high water content, clay becomes sticky like (cohesive) and soften. Therefore, clay stabilization is necessary to repair soil’s mechanical properties. In this research, lime is use as a stabilizer that contains the Ca+ element to bond bigger particles. Lime used is slaked lime Ca(OH)2. Clay used has liquid limitation (LL) value of 47.33%, plasticity index of 29.88% and CBR value 6.29. The results explain about 10% lime mixture variation gives the optimum stabilized clay with CBR value of 8.75%.

Structural transformations, composition anomalies and a dramatic collapse of linear polymer chains in dilute ethanol-water mixtures.

PubMed

Banerjee, Saikat; Ghosh, Rikhia; Bagchi, Biman

2012-03-29

Water-ethanol mixtures exhibit many interesting anomalies, such as negative excess partial molar volume of ethanol, excess sound absorption coefficient at low concentrations, and positive deviation from Raoult's law for vapor pressure, to mention a few. These anomalies have been attributed to different, often contradictory origins, but a quantitative understanding is still lacking. We show by computer simulation and theoretical analyses that these anomalies arise from the sudden emergence of a bicontinuous phase that occurs at a relatively low ethanol concentration of x(eth) ≈ 0.06-0.10 (that amounts to a volume fraction of 0.17-0.26, which is a significant range!). The bicontinuous phase is formed by aggregation of ethanol molecules, resulting in a weak phase transition whose nature is elucidated. We find that the microheterogeneous structure of the mixture gives rise to a pronounced nonmonotonic composition dependence of local compressibility and nonmonotonic dependence in the peak value of the radial distribution function of ethyl groups. A multidimensional free energy surface of pair association is shown to provide a molecular explanation of the known negative excess partial volume of ethanol in terms of parallel orientation and hence better packing of the ethyl groups in the mixture due to hydrophobic interactions. The energy distribution of the ethanol molecules indicates additional energy decay channels that explain the excess sound attenuation coefficient in aqueous alcohol mixtures. We studied the dependence of the solvation of a linear polymer chain on the composition of the water-ethanol solvent. We find that there is a sudden collapse of the polymer at x(eth) ≈ 0.05-a phenomenon which we attribute to the formation of the microheterogeneous structures in the binary mixture at low ethanol concentrations. Together with recent single molecule pulling experiments, these results provide new insight into the behavior of polymer chain and foreign solutes, such as enzymes, in aqueous binary mixtures.

Sandblasting nozzle

NASA Technical Reports Server (NTRS)

Perkins, G. S.; Pawlik, E. V.; Phillips, W. M. (Inventor)

1981-01-01

A nozzle for use with abrasive and/or corrosive materials is formed of sintered ceramic compositions having high temperature oxidation resistance, high hardness and high abrasion and corrosion resistance. The ceramic may be a binary solid solution of a ceramic oxide and silicon nitride, and preferably a ternary solid solution of a ceramic oxide, silicon nitride and aluminum nitride. The ceramic oxide is selected from a group consisting of Al2O3, Y2O3 and Cr2O3, or mixtures of those compounds. Titanium carbide particles are dispersed in the ceramic mixture before sintering. The nozzles are encased for protection from external forces while in use by a metal or plastic casing.

Separation of polar gases from nonpolar gases

DOEpatents

Kulprathipanja, Santi; Kulkarni, Sudhir S.

1986-01-01

Polar gases such as hydrogen sulfide, sulfur dioxide and ammonia may be separated from nonpolar gases such as methane, nitrogen, hydrogen or carbon dioxide by passing a mixture of polar and nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

Separation of polar gases from nonpolar gases

DOEpatents

Kulprathipanja, S.; Kulkarni, S.S.

1986-08-26

Polar gases such as hydrogen sulfide, sulfur dioxide and ammonia may be separated from nonpolar gases such as methane, nitrogen, hydrogen or carbon dioxide by passing a mixture of polar and nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

Imaging Effects of Neurotrophic Factor Genes on Brain Plasticity and Repair in Multiple Sclerosis

DTIC Science & Technology

2012-07-01

sensitive to focal and diffuse changes in brain tissue (including cortical thickness and subcortical volume measures, lesion volumetry , and voxel-based...sensitive to both focal and diffuse effects in gray and white matter, including cortical thickness and subcortical volume measures, lesion volumetry , and

Simulation of mixture microstructures via particle packing models and their direct comparison with real mixtures

NASA Astrophysics Data System (ADS)

Gulliver, Eric A.

The objective of this thesis to identify and develop techniques providing direct comparison between simulated and real packed particle mixture microstructures containing submicron-sized particles. This entailed devising techniques for simulating powder mixtures, producing real mixtures with known powder characteristics, sectioning real mixtures, interrogating mixture cross-sections, evaluating and quantifying the mixture interrogation process and for comparing interrogation results between mixtures. A drop and roll-type particle-packing model was used to generate simulations of random mixtures. The simulated mixtures were then evaluated to establish that they were not segregated and free from gross defects. A powder processing protocol was established to provide real mixtures for direct comparison and for use in evaluating the simulation. The powder processing protocol was designed to minimize differences between measured particle size distributions and the particle size distributions in the mixture. A sectioning technique was developed that was capable of producing distortion free cross-sections of fine scale particulate mixtures. Tessellation analysis was used to interrogate mixture cross sections and statistical quality control charts were used to evaluate different types of tessellation analysis and to establish the importance of differences between simulated and real mixtures. The particle-packing program generated crescent shaped pores below large particles but realistic looking mixture microstructures otherwise. Focused ion beam milling was the only technique capable of sectioning particle compacts in a manner suitable for stereological analysis. Johnson-Mehl and Voronoi tessellation of the same cross-sections produced tessellation tiles with different the-area populations. Control charts analysis showed Johnson-Mehl tessellation measurements are superior to Voronoi tessellation measurements for detecting variations in mixture microstructure, such as altered particle-size distributions or mixture composition. Control charts based on tessellation measurements were used for direct, quantitative comparisons between real and simulated mixtures. Four sets of simulated and real mixtures were examined. Data from real mixture was matched with simulated data when the samples were well mixed and the particle size distributions and volume fractions of the components were identical. Analysis of mixture components that occupied less than approximately 10 vol% of the mixture was not practical unless the particle size of the component was extremely small and excellent quality high-resolution compositional micrographs of the real sample are available. These methods of analysis should allow future researchers to systematically evaluate and predict the impact and importance of variables such as component volume fraction and component particle size distribution as they pertain to the uniformity of powder mixture microstructures.

Ion Permeability of Artificial Membranes Evaluated by Diffusion Potential and Electrical Resistance Measurements

ERIC Educational Resources Information Center

Shlyonsky, Vadim

2013-01-01

In the present article, a novel model of artificial membranes that provides efficient assistance in teaching the origins of diffusion potentials is proposed. These membranes are made of polycarbonate filters fixed to 12-mm plastic rings and then saturated with a mixture of creosol and "n"-decane. The electrical resistance and potential…

A mixture of five phthalate esters inhibits fetal testicular testosterone production in a cummulative manner consistent with their predicted reproductive toxicity in the Sprague Dawley rat

EPA Science Inventory

Phthalate diesters are plasticizers to which humans are ubiquitously exposed. Exposure to certain phthalates during sexual differentiation causes reproductive tract malformations in male rats. In the fetal rat, exposure to the phthalates benzylbutyl (BBP), di(n)butyl (DBP), and...

Opportunities for composites from recycled wastewood-based resources: A problem analysis and research plan

Treesearch

Roger M. Rowell; Henry Spelter; Rodger A. Arola; Phil Davis; Tom Friberg; Richard W. Hemingway; Tim Rials; David Luneke; Ramani Narayan; John Simonsen; Don White

1993-01-01

There are many opportunities to produce composites from recycled biobased fiber. The fiber can be used alone to make low-cost and high-performance composites, combined with inorganic materials, or combined with other recycled materials, such as plastics, to produce mixtures, compatibilized blends, and alloys. This report describes the resources available: problems...

CYCLIC AMP-DEPENDENT PROTEIN KINASE INDUCTION BY POLYCHLORINATED BIPHENYLS (PCBS) STIMULATES CREB PHOSPHORYLATION VIA A CALCIUM-DEPENDENT, PKC-INDEPENDENT PATHWAY IN CORTICAL NEURONS.

EPA Science Inventory

We have previously demonstrated that the PCB mixture, Aroclor 1254 (A1254), increases the phosphorylated form of CREB (pCREB), the cAMP-responsive element binding protein. This transcription factor is important in nervous system development and plasticity. Phosphorylation
of C...

Modeling plasticity by non-continuous deformation

NASA Astrophysics Data System (ADS)

Ben-Shmuel, Yaron; Altus, Eli

2017-10-01

Plasticity and failure theories are still subjects of intense research. Engineering constitutive models on the macroscale which are based on micro characteristics are very much in need. This study is motivated by the observation that continuum assumptions in plasticity in which neighbour material elements are inseparable at all-time are physically impossible, since local detachments, slips and neighbour switching must operate, i.e. non-continuous deformation. Material microstructure is modelled herein by a set of point elements (particles) interacting with their neighbours. Each particle can detach from and/or attach with its neighbours during deformation. Simulations on two- dimensional configurations subjected to uniaxial compression cycle are conducted. Stochastic heterogeneity is controlled by a single "disorder" parameter. It was found that (a) macro response resembles typical elasto-plastic behaviour; (b) plastic energy is proportional to the number of detachments; (c) residual plastic strain is proportional to the number of attachments, and (d) volume is preserved, which is consistent with macro plastic deformation. Rigid body displacements of local groups of elements are also observed. Higher disorder decreases the macro elastic moduli and increases plastic energy. Evolution of anisotropic effects is obtained with no additional parameters.

The effect of plastic strain on the evolution of crystallographic texture in Zircaloy-2

NASA Astrophysics Data System (ADS)

Ballinger, R. G.; Lucas, G. E.; Pelloux, R. M.

1984-09-01

The evolution of crystallographic texture during plastic deformation was investigated in Zircaloy-2 using X-ray and metallographic techniques. Inverse pole figures, the resolved fraction of basal poles, and the volume fraction of twinned material, were determined as a function of plastic strain for several strain paths and initial textures at 298 K and 623 K. Incremental transverse platic strain ratios ( R) were mesured as a function of plastic strain. Texture rotation occurs early in the deformation process, after as little as 1.5% plastic strain. For compressive plastic strains, the resolved fraction of basal poles increases in the direction parallel to the strain axis. For tensile plastic strains, the resolved fraction of basal poles decreases in the direction parallel to the strain axis. The rate of change of the resolved fraction of basal poles with plastic strain is a function of the initial resolved fraction of basal poles. The texture rotation can be explained by considering the operation of the principal tensile twinning systems, {101¯2}<1¯011>.

Microstructure-property relationships and constitutive response of plastically graded case hardened steels

NASA Astrophysics Data System (ADS)

Klecka, Michael A.

Case hardened materials, popularly used in many demanding engineering applications such as bearings, gears, and wear/impact surfaces, have high surface hardness and a gradient in material properties (hardness, yield strength, etc.) as a function of depth; therefore, they behave as plastically graded materials. In the current study, two different commercially available case carburized steels along with two through hardened steels are characterized to obtain relationships among the volume fraction of subsurface carbides, indentation hardness, elastic modulus, and yield strength as a function of depth. A variety of methods including microindentation, nanoindentation, ultrasonic measurements, compression testing, rule of mixtures, and upper and lower bound models are used to determine the relationships for elastic modulus and compare the experimental results with model predictions. In addition, the morphology, composition, and properties of the carbide particles are also determined. The gradient in hardness with depth in graded materials is commonly determined using microindentation on the cross-section of the material which contains the gradation in microstructure or composition. In the current study, a novel method is proposed to predict the hardness gradient profile using solely surface indentations at a range of loads. The method does not require the graded material to be sectioned, and has practical utility in the surface heat-treatment industry. For a material with a decreasing gradient in hardness, higher indent loads result in a lower measured hardness due to the influence of the softer subsurface layers. A power-law model is presented which relates the measured surface indentation hardness under increasing load to the subsurface gradient in hardness. A coordinated experimental and numerical study is presented to extract the constitutive response of graded materials, utilizing relationships between hardness, plastic deformation, and strain hardening response. The average plastic strain induced by an indent is shown to be an effective measure of the representative plastic strain, which is used in order to relate hardness to yield strength in both virgin and plastically deformed materials. It is shown that the two carburized steels contain gradients in yield strength, but constant strain hardening exponent with depth. The resulting model of material behavior is used to characterize the influence of specific gradients in material properties on the surface indentation behavior under increasing indentation loads. It is also shown that the response of the material is not greatly influenced by strain hardening exponent, while a gradient in strain hardening ability only has minimal impact. Gradients in elastic properties are also shown to have negligible influence for a fixed gradient in hardness. The depth of subsurface plastic deformation is shown to increase with sharper gradients in hardness, but is not altered by gradients in elastic properties. The proposed approach is not specific to case hardened materials and can be used to determine the subsurface hardness gradient for any graded material.

Crystal plasticity simulation of Zirconium tube rolling using multi-grain representative volume element

NASA Astrophysics Data System (ADS)

Isaenkova, Margarita; Perlovich, Yuriy; Zhuk, Dmitry; Krymskaya, Olga

2017-10-01

The rolling of Zirconium tube is studied by means of the crystal plasticity viscoplastic self-consistent (VPSC) constitutive modeling. This modeling performed by a dislocation-based constitutive model and a spectral solver using open-source simulation of DAMASK kit. The multi-grain representative volume elements with periodic boundary conditions are used to predict the texture evolution and distributions of strain and stresses. Two models for randomly textured and partially rolled material are deformed to 30% reduction in tube wall thickness and 7% reduction in tube diameter. The resulting shapes of the models are shown and distributions of strain are plotted. Also, evolution of grain's shape during deformation is shown.

Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

PubMed

Rios, Pedro; Stuart, Julie Ann; Grant, Ed

2003-12-01

Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

Recent technology and usage of plastic lenses in image taking objectives

NASA Astrophysics Data System (ADS)

Yamaguchi, Susumu; Sato, Hiroshi; Mori, Nobuyoshi; Kiriki, Toshihiko

2005-09-01

Recently, plastic lenses produced by injection molding are widely used in image taking objectives for digital cameras, camcorders, and mobile phone cameras, because of their suitability for volume production and ease of obtaining an advantage of aspherical surfaces. For digital camera and camcorder objectives, it is desirable that there is no image point variation with the temperature change in spite of employing several plastic lenses. At the same time, due to the shrinking pixel size of solid-state image sensor, there is now a requirement to assemble lenses with high accuracy. In order to satisfy these requirements, we have developed 16 times compact zoom objective for camcorder and 3 times class folded zoom objectives for digital camera, incorporating cemented plastic doublet consisting of a positive lens and a negative lens. Over the last few years, production volumes of camera-equipped mobile phones have increased substantially. Therefore, for mobile phone cameras, the consideration of productivity is more important than ever. For this application, we have developed a 1.3-mega pixels compact camera module with macro function utilizing the advantage of a plastic lens that can be given mechanically functional shape to outer flange part. Its objective consists of three plastic lenses and all critical dimensions related to optical performance can be determined by high precise optical elements. Therefore this camera module is manufactured without optical adjustment in automatic assembling line, and achieves both high productivity and high performance. Reported here are the constructions and the technical topics of image taking objectives described above.

An analysis of leading, lagging, and coincident economic indicators in the United States and its relationship to the volume of plastic surgery procedures performed.

PubMed

Hoppe, Ian C; Pastor, Craig J; Paik, Angie M

2012-10-01

In plastic surgery, 2 predominant practice environments exist, namely, the academic setting and private practice. These 2 groups cater their practice toward the needs and demands of 2 very different patient populations. The goal of this paper is to examine well-established economic indicators and delineate their relationship, if any, with the volume of different plastic surgical procedures performed in the United States. Information from the American Society of Plastic Surgeons' annual reports on plastic surgery statistics was collected from the year 2000 through 2010 and compared to readily available and established economic indicators. There was a significant positive relationship with total cosmetic procedures and gross domestic product (GDP), GDP per capita, personal income, consumer price index (CPI) (all), and CPI (medical). There was a significant positive relationship between cosmetic surgical procedures and the issuance of new home permits and the average prime rate charged by banks. There was a significant positive relationship with cosmetic minimally invasive procedures and GDP, GDP per capita, personal income, CPI (all), and CPI (medical). There was a significant negative relationship between reconstructive procedures and GDP, GDP per capita, personal income, CPI (all), and CPI (medical). Cosmetic minimally invasive procedures seem to be decided on relatively quickly during good economic times. Cosmetic surgical procedures seem to be more planned and less related to the economic environment. The plastic surgeon may use this relationship to tailor the focus of his or her practice to be best situated for economic fluctuations.

Measurement of early age shrinkage of Virginia concrete mixtures.

DOT National Transportation Integrated Search

2008-01-01

Concrete volume changes throughout its service life. The total in-service volume change is the resultant of applied loads and shrinkage. When loaded, concrete undergoes an instantaneous elastic deformation and a slow inelastic deformation called cree...

High-volume fly ash concrete.

DOT National Transportation Integrated Search

2013-06-01

The objective of the proposed study is to design, test, and evaluate high-volume fly ash concrete mixtures. Traditional specifications : limit the amount of fly ash to 40% or less cement replacement. This program attempts to increase the ash content ...

Thermodynamic properties of deep eutectic solvent and ionic liquid mixtures at temperatures from 293.15 K to 343.15 K

NASA Astrophysics Data System (ADS)

Achsah, R. S.; Shyam, S.; Mayuri, N.; Anantharaj, R.

2018-04-01

Deep eutectic solvents (DES) and ionic liquids (ILs) have their applications in various fields of research and in industries due to their attractive physiochemical properties. In this study, the combined thermodynamic properties of DES (choline chloride-glycerol) + IL1 (1-butyl-3-methylimiazolium acetate) and DES(choline chloride-glycerol) + IL2 (1-ethyl-3-methylimadzolium ethyl sulphate) have been studied. The thermodynamic properties such as excess molar volume, partial molar volume, excess partial molar volume and apparent molar volume were calculated for different mole fractions ranging from 0 to 1 and varying temperatures from 293.15 K to 343.15 K. In order to know the solvent properties of DESs and ILs mixtures at different temperatures and their molecular interactions to enhance the solvent performance and process efficiency at fixed composition and temperature the thermodynamic properties were analyzed.

Methods for synthesizing microporous crystals and microporous crystal membranes

DOEpatents

Dutta, Prabir; Severance, Michael; Sun, Chenhu

2017-02-07

A method of making a microporous crystal material, comprising: a. forming a mixture comprising NaOH, water, and one or more of an aluminum source, a silicon source, and a phosphate source, whereupon the mixture forms a gel; b. heating the gel for a first time period, whereupon a first volume of water is removed from the gel and micoroporous crystal nuclei form, the nuclei having a framework; and c.(if a membrane is to be formed) applying the gel to a solid support seeded with microporous crystals having a framework that is the same as the framework of the nuclei; d. heating the gel for a second time period. during which a second volume of water is added to the gel; wherein the rate of addition of the second volume of water is between about 0.5 and about 2.0 fold the rate of removal of the first volume of water.

Chemistry of Aviation Fuels

NASA Technical Reports Server (NTRS)

Knepper, Bryan; Hwang, Soon Muk; DeWitt, Kenneth J.

2004-01-01

Minimum ignition energies of various methanol/air mixtures were measured in a temperature controlled constant volume combustion vessel using a spark ignition method with a spark gap distance of 2 mm. The minimum ignition energies decrease rapidly as the mixture composition (equivalence ratio, Phi) changes from lean to stoichiometric, reach a minimum value, and then increase rather slowly with Phi. The minimum of the minimum ignition energy (MIE) and the corresponding mixture composition were determined to be 0.137 mJ and Phi = 1.16, a slightly rich mixture. The variation of minimum ignition energy with respect to the mixture composition is explained in terms of changes in reaction chemistry.

Development of an economical, thin, quiet, long-lasting, high friction surface layer, volume 1 : mix design and lab performance testing.

DOT National Transportation Integrated Search

2013-03-01

This project developed and evaluated four new asphalt concrete (AC) mixtures that use locally available : aggregates whenever possible with the ultimate goal of a cost-effective mixture that also improves pavement : performance. Although numerous tac...

Wetting and elasto-plasticity based sculpture of liquid marbles.

PubMed

Liu, Jianlin; Zuo, Pingcheng

2016-02-01

As an emerging material with exotic properties, liquid marble holds great potential for such areas as microfluidics, stimuli-responsive sensors, micro-chemical reactors, micro-bioreactors, energy harvesting devices, and mechanical structures. In this study, we mainly concentrate on the mechanical behaviors, such as elasto-plasticity of liquid marble with the decrease of liquid volume. The contact radius with the substrate and Young's contact angle of liquid marble are both measured with the change of water volume, and those of a water droplet are compared. The mechanism for the different responses for liquid marble and water droplet is clarified according to the mechanics analysis. Moreover, it is found that liquid marble can behave like an elasto-plastic material when the particle surface density is big enough. Based upon this fact, liquid marble can be sculpted to all kinds of special shapes as expected. These investigations may cast new light on how to engineer multifunctional materials and devices, which are beneficial to microprinting and micromachining.

Hidden plastics of Lake Ontario, Canada and their potential preservation in the sediment record.

PubMed

Corcoran, Patricia L; Norris, Todd; Ceccanese, Trevor; Walzak, Mary Jane; Helm, Paul A; Marvin, Chris H

2015-09-01

Microplastics are a source of environmental pollution resulting from degradation of plastic products and spillage of resin pellets. We report the amounts of microplastics from various sites of Lake Ontario and evaluate their potential for preservation in the sediment record. A total of 4635 pellets were sampled from the Humber Bay shoreline on three sampling dates. Pellet colours were similar to those from the Humber River bank, suggesting that the river is a pathway for plastics transport into Lake Ontario. Once in the lake, high density microplastics, including mineral-polyethylene and mineral-polypropylene mixtures, sink to the bottom. The minerals may be fillers that were combined with plastics during production, or may have adsorbed to the surfaces of the polymers in the water column or on the lake bottom. Based on sediment depths and accumulation rates, microplastics have accumulated in the offshore region for less than 38 years. Their burial increases the chance of microplastics preservation. Shoreline pellets may not be preserved because they are mingled with organic debris that is reworked during storm events. Copyright © 2015 Elsevier Ltd. All rights reserved.

Photothermal microfluidic cantilever deflection spectroscopy reflecting clustering mechanism of ethanol water mixtures

NASA Astrophysics Data System (ADS)

Ghoraishi, Maryam; Hawk, John; Thundat, Thomas

Aqueous mixture of alcohol is a typical prototype for biomolecules, micelle formation, and structural stability of proteins. Therefore, Short chain alcohols such as EtOH have been used as a simple model for understanding of more complex aqueous biomolecules. Here we study vibrational energy peaks of EtOH water binary mixtures using micromechanical calorimetric spectroscopy using bimaterial microfluidic cantilevers (BMC). The IR spectra of EtOH-water are experimentally collected employing a BMC as concentration of EtOH changes from 20-100 wt%. As concentration of EtOH varies in the mixture, considerable shifts in the wavenumber at IR absorption peak maxima are reported. The experimentally measured shifts in the wavenumber at IR absorption peak maxima are related to changes in dipole moment (μ) of EtOH at different concentration. The relationship between IR absorption wavenumber for both anti and gauche conformers of EtOH, and inverse dipole moment, 1/ μ, of EtOH at different concentrations follows a power law dependence. Our technique offers a platform to investigate dipole effect on molecular vibrations of mixtures in confined picoliter volumes, previously unexplored with other analytical techniques due to limitations of volume under study.

Quantification of synthesized hydration products using synchrotron microtomography and spectral analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deboodt, Tyler; Ideker, Jason H.; Isgor, O. Burkan

2017-12-01

The use of x-ray computed tomography (CT) as a standalone method has primarily been used to characterize pore structure, cracking and mechanical damage in cementitious systems due to low contrast in the hydrated phases. These limitations have resulted in the inability to extract quantifiable information on such phases. The goal of this research was to address the limitations caused by low contrast and improving the ability to distinguish the four primary hydrated phases in portland cement; C-S-H, calcium hydroxide, monosulfate, and ettringite. X-ray CT on individual layers, binary mixtures of phases, and quaternary mixtures of phases to represent a hydratedmore » portland cement paste were imaged with synchrotron radiation. Known masses of each phase were converted to a volume and compared to the segmented image volumes. It was observed that adequate contrast in binary mixing of phases allowed for segmentation, and subsequent image analysis indicated quantifiable volumes could be extracted from the tomographic volume. However, low contrast was observed when C-S-H and monosulfate were paired together leading to difficulties segmenting in an unbiased manner. Quantification of phases in quaternary mixtures included larger errors than binary mixes due to histogram overlaps of monosulfate, C-S-H, and calcium hydroxide.« less

Is There a Safe Lipoaspirate Volume? A Risk Assessment Model of Liposuction Volume as a Function of Body Mass Index.

PubMed

Chow, Ian; Alghoul, Mohammed S; Khavanin, Nima; Hanwright, Philip J; Mayer, Kristen E; Hume, Keith M; Murphy, Robert X; Gutowski, Karol A; Kim, John Y S

2015-09-01

No concrete data exist to support a specific volume at which liposuction becomes unsafe; surgeons rely on their own estimates, professional organization advisories, or institutional or government-imposed restrictions. This study represents the first attempt to quantify the comprehensive risk associated with varying liposuction volumes and its interaction with body mass index. Suction-assisted lipectomies were identified from the Tracking Operations and Outcomes for Plastic Surgeons database. Multivariate regression models incorporating the interaction between liposuction volume and body mass index were used to assess the influence of liposuction volume on complications and to develop a tool that returns a single adjusted odds ratio for any combination of body mass index and liposuction volume. Recursive partitioning was used to determine whether exceeding a threshold in liposuction volume per body mass index unit significantly increased complications. Sixty-nine of 4534 patients (1.5 percent) meeting inclusion criteria experienced a postoperative complication. Liposuction volume and body mass index were significant independent risk factors for complications. With progressively higher volumes, increasing body mass index reduced risk (OR, 0.99; 95 percent CI, 0.98 to 0.99; p = 0.007). Liposuction volumes in excess of 100 ml per unit of body mass index were an independent predictor of complications (OR, 4.58; 95 percent CI, 2.60 to 8.05; p < 0.001). Liposuction by board-certified plastic surgeons is safe, with a low risk of life-threatening complications. Traditional liposuction volume thresholds do not accurately convey individualized risk. The authors' risk assessment model demonstrates that volumes in excess of 100 ml per unit of body mass index confer an increased risk of complications. Therapeutic, III.

Laboratory and exterior decay of wood plastic composite boards: voids analysis and computed tomography

Treesearch

Grace Sun; Rebecca E. Ibach; Meghan Faillace; Marek Gnatowski; Jessie A. Glaeser; John Haight

2016-01-01

After exposure in the field and laboratory soil block culture testing, the void content of wood–plastic composite (WPC) decking boards was compared to unexposed samples. A void volume analysis was conducted based on calculations of sample density and from micro-computed tomography (microCT) data. It was found that reference WPC contains voids of different sizes from...

Flexible plastic bioreactors for photobiological hydrogen production by hydrogenase-deficient cyanobacteria.

PubMed

Kitashima, Masaharu; Masukawa, Hajime; Sakurai, Hidehiro; Inoue, Kazuhito

2012-01-01

Uptake hydrogenase mutant cells of the cyanobacterium Nostoc sp. PCC 7422 photobiologically produced H(2) catalyzed by nitrogenase for several days in H(2)-barrier transparent plastic bags, and accumulated H(2) in the presence of O(2) evolved by photosynthesis. Their H(2) production activity was higher in the sealed flexible bags than in stoppered serum bottles of fixed gas volume.

Measurement of activity coefficients of mixtures by head-space gas chromatography: general procedure.

PubMed

Luis, Patricia; Wouters, Christine; Van der Bruggen, Bart; Sandler, Stanley I

2013-08-09

Head-space gas chromatography (HS-GC) is an applicable method to perform vapor-liquid equilibrium measurements and determine activity coefficients. However, the reproducibility of the data may be conditioned by the experimental procedure concerning to the automated pressure-balanced system. The study developed in this work shows that a minimum volume of liquid in the vial is necessary to ensure the reliability of the activity coefficients since it may become a parameter that influences the magnitude of the peak areas: the helium introduced during the pressurization step may produce significant variations of the results when too small volume of liquid is selected. The minimum volume required should thus be evaluated prior to obtain experimentally the concentration in the vapor phase and the activity coefficients. In this work, the mixture acetonitrile-toluene is taken as example, requiring a sample volume of more than 5mL (about more than 25% of the vial volume). The vapor-liquid equilibrium and activity coefficients of mixtures at different concentrations (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 molar fraction) and four temperatures (35, 45, 55 and 70°C) have been determined. Relative standard deviations (RSD) lower than 5% have been obtained, indicating the good reproducibility of the method when a sample volume larger than 5mL is used. Finally, a general procedure to measure activity coefficients by means of pressure-balanced head-space gas chromatography is proposed. Copyright © 2013 Elsevier B.V. All rights reserved.

Test Plan Development for Plastic Ammunition Containers. Volume 1

DTIC Science & Technology

1989-03-15

1850 Black Canyon Stage¶I Packaging division (SMCAR-AEP) Picatinny Phoenix, Arizona 85027 Arsenal, New Jersey 07806-5000 86. NAME OF FUNDING...packaging containers. The report is presented in two separate volumes. Volume I contains the Final Technical Report and includes the analysis of... Division of the U.S. Army Armament Research, Development and Engineering Center. Mr. Jasper C. Griggs and Mr. D. E. Jones served as technical consultants

The physical foundation of FN = kh(3/2) for conical/pyramidal indentation loading curves.

PubMed

Kaupp, G

2016-01-01

A physical deduction of the FN = kh(3/2) relation (where FN is normal force, k penetration resistance, and h penetration depth) for conical/pyramidal indentation loading curves has been achieved on the basis of elementary mathematics. The indentation process couples the productions of volume and pressure to the displaced material that often partly plasticizes due to such pressure. As the pressure/plasticizing depends on the indenter volume, it follows that FN = FNp(1/3) · FNV(2/3), where the index p stands for pressure/plasticizing and V for indentation volume. FNp does not contribute to the penetration, only FNV. The exponent 2/3 on FNV shows that while FN is experimentally applied; only FN(2/3) is responsible for the penetration depth h. Thus, FN = kh(3/2) is deduced and the physical reason is the loss of FN(1/3) for the depth. Unfortunately, this has not been considered in teaching, textbooks, and the previous deduction of numerous common mechanical parameters, when the Love/Sneddon deductions of an exponent 2 on h were accepted and applied. The various unexpected experimental verifications and applications of the correct exponent 3/2 are mentioned and cited. Undue mechanical parameters require correction not only for safety reasons. © Wiley Periodicals, Inc.

The plasticity of extracellular fluid homeostasis in insects.

PubMed

Beyenbach, Klaus W

2016-09-01

In chemistry, the ratio of all dissolved solutes to the solution's volume yields the osmotic concentration. The present Review uses this chemical perspective to examine how insects deal with challenges to extracellular fluid (ECF) volume, solute content and osmotic concentration (pressure). Solute/volume plots of the ECF (hemolymph) reveal that insects tolerate large changes in all three of these ECF variables. Challenges beyond those tolerances may be 'corrected' or 'compensated'. While a correction simply reverses the challenge, compensation accommodates the challenge with changes in the other two variables. Most insects osmoregulate by keeping ECF volume and osmotic concentration within a wide range of tolerance. Other insects osmoconform, allowing the ECF osmotic concentration to match the ambient osmotic concentration. Aphids are unique in handling solute and volume loads largely outside the ECF, in the lumen of the gut. This strategy may be related to the apparent absence of Malpighian tubules in aphids. Other insects can suspend ECF homeostasis altogether in order to survive extreme temperatures. Thus, ECF homeostasis in insects is highly dynamic and plastic, which may partly explain why insects remain the most successful class of animals in terms of both species number and biomass. © 2016. Published by The Company of Biologists Ltd.

Ammonia modification for flotation separation of polycarbonate and polystyrene waste plastics.

PubMed

Wang, Chong-Qing; Wang, Hui; Gu, Guo-Hua; Lin, Qing-Quan; Zhang, Ling-Ling; Huang, Luo-Luo; Zhao, Jun-Yao

2016-05-01

A promising method, ammonia modification, was developed for flotation separation of polycarbonate (PC) and polystyrene (PS) waste plastics. Ammonia modification has little effect on flotation behavior of PS, while it changes significantly that of PC. The PC recovery in the floated product drops from 100% to 3.17% when modification time is 13min and then rises to 100% after longer modification. The mechanism of ammonia modification was studied by contact angle, and Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) measurements. Contact angle of PC indicates the decline of PC recovery in the floated product is ascribed to an increase in surface wettability. FT-IR and XPS spectra suggest that ammonia modification causes chemical reactions occurred on PC surface. Flotation behavior of ammonia-modified PC and PS was investigated with respect to flotation time, frother concentration and particle sizes. Flotation separation of PC and PS waste plastics was conducted based on the flotation behavior of single plastic. PC and PS mixtures with different particle sizes are separated efficiently, implying that the technology possesses superior applicability to particle sizes of plastics. The purity of PS and PC is up to 99.53% and 98.21%, respectively, and the recovery of PS and PC is larger than 92.06%. A reliable, cheap and effective process is proposed for separation of PC and PS waste plastics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Predicting the apparent viscosity and yield stress of digested and secondary sludge mixtures.

PubMed

Eshtiaghi, Nicky; Markis, Flora; Zain, Dwen; Mai, Kiet Hung

2016-05-15

The legal banning of conventional sludge disposal methods such as landfill has led to a global movement towards achieving a sustainable sludge management strategy. Reusing sludge for energy production (biogas production) through the anaerobic digestion of sludge can provide a sustainable solution. However, for the optimum performance of digesters with minimal use of energy input, operating conditions must be regulated in accordance with the rheological characteristics of the sludge. If it is assumed that only secondary sludge enters the anaerobic digesters, an impact of variations to the solids concentration and volume fraction of each sludge type must be investigated to understand how the apparent viscosity and yield stress of the secondary and digested sludge mixture inside the digesters changes. In this study, five different total solids concentration of secondary and digested sludge were mixed at different digested sludge volume fractions ranging from 0 to 1. It was found that if secondary sludge was mixed with digested sludge at the same total solids concentration, the apparent viscosity and the yield stress of the mixture increased exponentially by increasing the volume fraction of digested sludge. However, if secondary sludge was added to digested sludge with a different solids concentration, the apparent viscosity and yield stress of the resulting mixed sludge was controlled by the concentrated sludge regardless of its type. Semi - empirical correlations were proposed to predict the apparent viscosity and yield stress of the mixed digested and secondary sludge. A master curve was also developed to predict the flow behaviour of sludge mixtures regardless of the total solid concentration and volume fraction of each sludge type within the studied solids concentration range of 1.4 and 7%TS. This model can be used for digesters optimization and design by predicting the rheology of sludge mixture inside digester. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical thermodynamics of ultrasound speed in solutions and liquid mixtures.

PubMed

Reis, João Carlos R; Santos, Angela F S; Lampreia, Isabel M S

2010-02-01

A comprehensive formalism is developed to treat thermodynamically speed of ultrasound data for solutions and liquid mixtures. For solutions, the apparent speed of ultrasound of a solute is introduced and proposed to take the place of empirically defined quantities. The partial speed of ultrasound of a solute is defined and related to the partial molar volume and partial molar isentropic compression. For liquid mixtures, the concept of speed of sound before mixing pure liquids is presented and used to define the change in speed of ultrasound upon ideal mixing, which is predicted to be generally a negative quantity. A new thermodynamic equation is derived linking the values for excess speed of ultrasound, excess molar volume and excess molar isentropic compression of a mixture, and its applications are discussed. Ideal and excess apparent speeds of ultrasound, as well as ideal and excess partial speeds of ultrasound, are defined for substances making up a liquid mixture. Accurate speeds of ultrasound in 31 mixtures of water with the amphiphile 2-(ethylamino)ethanol at 293.15 K are reported. These data are used to demonstrate the ability of the apparent speed of ultrasound to describe the impact of solutes on sonic properties of solutions and the advantages of analysing thermodynamic properties of binary liquid mixtures in terms of the dependence on composition of Balankina's ratios between excess and ideal values. It is concluded that the new thermodynamic functions defined for speeds of ultrasound in solutions and liquid mixtures give, at the least, equivalent information on molecular aspects to the usual functions related to the isentropic compressibility, without needing density data for this purpose.

Predictions of glass transition temperature for hydrogen bonding biomaterials.

PubMed

van der Sman, R G M

2013-12-19

We show that the glass transition of a multitude of mixtures containing hydrogen bonding materials correlates strongly with the effective number of hydroxyl groups per molecule, which are available for intermolecular hydrogen bonding. This correlation is in compliance with the topological constraint theory, wherein the intermolecular hydrogen bonds constrain the mobility of the hydrogen bonded network. The finding that the glass transition relates to hydrogen bonding rather than free volume agrees with our recent finding that there is little difference in free volume among carbohydrates and polysaccharides. For binary and ternary mixtures of sugars, polyols, or biopolymers with water, our correlation states that the glass transition temperature is linear with the inverse of the number of effective hydroxyl groups per molecule. Only for dry biopolymer/sugar or sugar/polyol mixtures do we find deviations due to nonideal mixing, imposed by microheterogeneity.

Synergistic rate boosting of collagen fibrillogenesis in heterogeneous mixtures of crowding agents.

PubMed

Dewavrin, Jean-Yves; Abdurrahiem, Muhammed; Blocki, Anna; Musib, Mrinal; Piazza, Francesco; Raghunath, Michael

2015-03-26

The competition for access to space that arises between macromolecules is the basis of the macromolecular crowding phenomenon, known to modulate biochemical reactions in subtle ways. Crowding is a highly conserved physiological condition in and around cells in metazoans, and originates from a mixture of heterogeneous biomolecules. Here, using collagen fibrillogenesis as an experimental test platform and ideas from the theory of nonideal solutions, we show that an entropy-based synergy is created by a mixture of two different populations of artificial crowders, providing small crowders with extra volume occupancy when in the vicinity of bigger crowders. We present the physiological mechanism by which synergistic effects maximize volume exclusion with the minimum amount of heterogeneous crowders, demonstrating how the evolutionarily optimized crowded conditions found in vivo can be reproduced effectively in vitro.

Study of thermodynamic and transport properties of binary liquid mixture of diesel with biodiesel at 298.15K

NASA Astrophysics Data System (ADS)

Suthar, Shyam Sunder; Purohit, Suresh

2018-05-01

Properties of diesel and biodiesel (produced from corn oil) are used. Densities and viscosities of binary mixture of diesel with biodiesel (produced from corn oil) have been computed by using liquid binary mixture law over the entire range of compositions at T=298.15K and atmospheric pressure. From the computed values of density and viscosities, viscosity deviation (Δη), the excess molar volume (VE) and excess Gibbs energy of activation of viscous flow (ΔG#E) have been calculated. The results of excess volume, excess Gibbs energy of activation of viscous flow and viscosity deviation have been fitted to Redlich -Kister models to estimate the binary coefficients. The results are communicated in terms of the molecular interactions and the best suited composition has been found.

Theoretical and practical aspects of improving the durability of steel reinforcement in transport designs, using passivation and plasticizing chemical additives

NASA Astrophysics Data System (ADS)

Velichko, Evgenij; Talipov, Linar

2017-10-01

The article deals with the problem of steel reinforcement corrosion in reinforced concrete structures exposed to aggressive media, in particular in reinforced concrete construction of transport infrastructure, in snowy areas, and subject to the influence of chlorides contained in applied deicing agents. Basic schemes for preventing the reinforcement corrosion in reinforced-concrete structures have been considered and analyzed. Prospects of primary protection against corrosion of reinforcement by introducing chemical additives with plasticizing/passivating action in a concrete mixture with mixing water have been considered in detail. The physical/chemical mechanism of the protective action of a superplasticizer together with a passivator has been highlighted.

Richard B. Russell Dam and Lake, Savannah River, Georgia and South Carolina Final Foundation Report, Concrete Dam, Embankments and Powerhouse. Volume 1. Text and Plates

DTIC Science & Technology

1989-10-03

explosive and was initiated with prmmord. Tovex 1. a water gel explosive in 50-foot long. 1-inch diameter, plastic tubes with internal primmnrd was tried an...iM then covered with plastic and thi ea coered with concrete (the tranck did not co ct) with a thicknes of aprodi tely 3 feet. A total of 114 cubc...upstrem slope remained to be controll.MAter the concrete had cured, the plastic e rmoved from the top of the cncrete aggregate and appolximately 1 foot

On a phase field approach for martensitic transformations in a crystal plastic material at a loaded surface

NASA Astrophysics Data System (ADS)

Schmitt, Regina; Kuhn, Charlotte; Müller, Ralf

2017-07-01

A continuum phase field model for martensitic transformations is introduced, including crystal plasticity with different slip systems for the different phases. In a 2D setting, the transformation-induced eigenstrain is taken into account for two martensitic orientation variants. With aid of the model, the phase transition and its dependence on the volume change, crystal plastic material behavior, and the inheritance of plastic deformations from austenite to martensite are studied in detail. The numerical setup is motivated by the process of cryogenic turning. The resulting microstructure qualitatively coincides with an experimentally obtained martensite structure. For the numerical calculations, finite elements together with global and local implicit time integration scheme are employed.

Iron coated sand/glauconite filters for phosphorus removal from artificially drained agricultural fields

NASA Astrophysics Data System (ADS)

Vandermoere, Stany; De Neve, Stefaan

2016-04-01

Flanders (Belgium) is confronted with reactive phosphorus concentrations in streams and lakes which are three to four times higher than the 0.1 ppm P limit set by the Water Framework Directive. Much of the excessive P input in surface waters is derived from agriculture. Direct P input from artificially drained fields (short-circuiting the buffering capacity of the subsoil) is suspected to be one of the major sources. We aim to develop simple and cheap filters that can be directly installed in the field to reduce P concentration from the drain water. Here we report on the performance of such filters tested at lab scale. As starting materials for the P filter, iron coated sand and acid pre-treated glauconite were used. These materials, both rich in Fe, were mixed in ratios of 75/25, 65/35, 50/50 and 0/100 (iron coated sand/glauconite ratio based on weight basis) and filled in plastic tubes. A screening experiment using the constant head method with a 0.01 M CaCl2 solution containing 1 ppm P showed that all four types of mixtures reduced the P concentration in the outflowing water to almost zero, and that the 75/25, 65/35 and 0/100 mixtures had a sufficiently large hydraulic conductivity of 0.9 to 6.0 cm/min, while the hydraulic conductivity of the 50/50 mixture was too low (< 0.4 cm/min). In a second experiment the iron coated sand and acid pre-treated glauconite were mixed in ratios of 75/25, 65/35 and 0/100 and filled in the same plastic tubes as in the first experiment. Subsequently a 0.01 M CaCl2 solution containing 1 ppm P was passed through the filters over several days, in amounts equivalent to half of the yearly water volume passing through the drains. This experiment firstly showed that in all cases the hydraulic conductivity fluctuated strongly: it decreased from 4.0-6.0 cm/min to 2.0-1.5 cm/min for the 75/25 filter, and to values < 0.4 cm/min for the 65/35 filter, whereas it increased from 0.8 to 1.4 cm/min for the 0/100 filter. Secondly, we observed a decrease in the P removal efficiency with time on each day for all filters: from 90% removal to 80% removal for the 75/25 and 65/35 filters, while for the 0/100 filter the P removal almost reduced to 0%. Based on these results the 75/25 (iron coated sand/glauconite) filter will be tested at field level, and additional research will be directed towards prediction of the evolution of hydraulic conductivity of the filter materials.

High pressure liquid chromatographic gradient mixer

DOEpatents

Daughton, Christian G.; Sakaji, Richard H.

1985-01-01

A gradient mixer which effects the continuous mixing of any two miscible solvents without excessive decay or dispersion of the resultant isocratic effluent or of a linear or exponential gradient. The two solvents are fed under low or high pressure by means of two high performance liquid chromatographic pumps. The mixer comprises a series of ultra-low dead volume stainless steel tubes and low dead volume chambers. The two solvent streams impinge head-on at high fluxes. This initial nonhomogeneous mixture is then passed through a chamber packed with spirally-wound wires which cause turbulent mixing thereby homogenizing the mixture with minimum "band-broadening".

High-pressure liquid chromatographic gradient mixer

DOEpatents

Daughton, C.G.; Sakaji, R.H.

1982-09-08

A gradient mixer effects the continuous mixing of any two miscible solvents without excessive decay or dispersion of the resultant isocratic effluent or of a linear or exponential gradient. The two solvents are fed under low or high pressure by means of two high performance liquid chromatographic pumps. The mixer comprises a series of ultra-low dead volume stainless steel tubes and low dead volume chambers. The two solvent streams impinge head-on at high fluxes. This initial nonhomogeneous mixture is then passed through a chamber packed with spirally-wound wires which cause turbulent mixing thereby homogenizing the mixture with minimum band-broadening.

Metal matrix composite of an iron aluminide and ceramic particles and method thereof

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneibel, Joachim H.

A metal matrix composite comprising an iron aluminide binder phase and a ceramic particulate phase such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide is made by heating a mixture of iron aluminide powder and particulates of one of the ceramics such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide in a alumina crucible at about 1450.degree. C. for about 15 minutes in an evacuated furnace and cooling the mixture to room temperature. The ceramic particulates comprise greater than 40 volume percent to about 99 volume percent of the metal matrix composite.

Metal matrix composite of an iron aluminide and ceramic particles and method thereof

DOEpatents

Schneibel, J.H.

1997-06-10

A metal matrix composite comprising an iron aluminide binder phase and a ceramic particulate phase such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide is made by heating a mixture of iron aluminide powder and particulates of one of the ceramics such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide in a alumina crucible at about 1,450 C for about 15 minutes in an evacuated furnace and cooling the mixture to room temperature. The ceramic particulates comprise greater than 40 volume percent to about 99 volume percent of the metal matrix composite.

Metal matrix composite of an iron aluminide and ceramic particles and method thereof

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneibel, J.H.

A metal matrix composite comprising an iron aluminide binder phase and a ceramic particulate phase such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide is made by heating a mixture of iron aluminide powder and particulates of one of the ceramics such as titanium diboride, zirconium diboride, titanium carbide and tungsten carbide in a alumina crucible at about 1,450 C for about 15 minutes in an evacuated furnace and cooling the mixture to room temperature. The ceramic particulates comprise greater than 40 volume percent to about 99 volume percent of the metal matrix composite.

Plasticity in mesophyll volume fraction modulates light-acclimation in needle photosynthesis in two pines.

PubMed

Niinemets, Ulo; Lukjanova, Aljona; Turnbull, Matthew H; Sparrow, Ashley D

2007-08-01

Acclimation potential of needle photosynthetic capacity varies greatly among pine species, but the underlying chemical, anatomical and morphological controls are not entirely understood. We investigated the light-dependent variation in needle characteristics in individuals of Pinus patula Schlect. & Cham., which has 19-31-cm long pendulous needles, and individuals of P. radiata D. Don., which has shorter (8-17-cm-long) stiffer needles. Needle nitrogen and carbon contents, mesophyll and structural tissue volume fractions, needle dry mass per unit total area (M(A)) and its components, volume to total area ratio (V/A(T)) and needle density (D = M(A)/(V/A(T))), and maximum carboxylase activity of Rubisco (V(cmax)) and capacity of photosynthetic electron transport (J(max)) were investigated in relation to seasonal mean integrated irradiance (Q(int)). Increases in Q(int) from canopy bottom to top resulted in proportional increases in both needle thickness and width such that needle total to projected surface area ratio, characterizing the efficiency of light interception, was independent of Q(int). Increased light availability also led to larger M(A) and nitrogen content per unit area (N(A)). Light-dependent modifications in M(A) resulted from increases in both V/A(T) and D, whereas N(A) changed because of increases in both M(A) and mass-based nitrogen content (N(M)) (N(A) = N(M)M(A)). Overall, the volume fraction of mesophyll cells increased with increasing irradiance and V/A(T) as the fraction of hypodermis and epidermis decreased with increasing needle thickness. Increases in M(A) and N(A) resulted in enhanced J(max) and V(cmax) per unit area in both species, but mass-based photosynthetic capacity increased only in P. patula. In addition, J(max) and V(cmax) showed greater plasticity in response to light in P. patula. Species differences in mesophyll volume fraction explained most of the variation in mass-based needle photosynthetic capacity between species, demonstrating that differences in plastic adjustments in mass-based photosynthetic activities among these representative individuals were mainly associated with contrasting investments in mesophyll cells. Greater area-based photosynthetic plasticity in P. patula relative to P. radiata was associated with larger increases in M(A) and mesophyll volume fraction with increasing irradiance. These data collectively demonstrate that light-dependent increases in mass-based nitrogen contents and photosynthetic activities were associated with an increased mesophyll volume fraction in needles at higher irradiances. They also emphasize the importance of light-dependent anatomical modifications in determining needle photosynthetic capacity.

Recycling of plastic waste: Presence of phthalates in plastics from households and industry.

PubMed

Pivnenko, K; Eriksen, M K; Martín-Fernández, J A; Eriksson, E; Astrup, T F

2016-08-01

Plastics recycling has the potential to substitute virgin plastics partially as a source of raw materials in plastic product manufacturing. Plastic as a material may contain a variety of chemicals, some potentially hazardous. Phthalates, for instance, are a group of chemicals produced in large volumes and are commonly used as plasticisers in plastics manufacturing. Potential impacts on human health require restricted use in selected applications and a need for the closer monitoring of potential sources of human exposure. Although the presence of phthalates in a variety of plastics has been recognised, the influence of plastic recycling on phthalate content has been hypothesised but not well documented. In the present work we analysed selected phthalates (DMP, DEP, DPP, DiBP, DBP, BBzP, DEHP, DCHP and DnOP) in samples of waste plastics as well as recycled and virgin plastics. DBP, DiBP and DEHP had the highest frequency of detection in the samples analysed, with 360μg/g, 460μg/g and 2700μg/g as the maximum measured concentrations, respectively. Among other, statistical analysis of the analytical results suggested that phthalates were potentially added in the later stages of plastic product manufacturing (labelling, gluing, etc.) and were not removed following recycling of household waste plastics. Furthermore, DEHP was identified as a potential indicator for phthalate contamination of plastics. Close monitoring of plastics intended for phthalates-sensitive applications is recommended if recycled plastics are to be used as raw material in production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Disposable rabbit

DOEpatents

Lewis, Leroy C.; Trammell, David R.

1986-01-01

A disposable rabbit for transferring radioactive samples in a pneumatic transfer system comprises aerated plastic shaped in such a manner as to hold a radioactive sample and aerated such that dissolution of the rabbit in a solvent followed by evaporation of the solid yields solid waste material having a volume significantly smaller than the original volume of the rabbit.

Disposal rabbit

DOEpatents

Lewis, L.C.; Trammell, D.R.

1983-10-12

A disposable rabbit for transferring radioactive samples in a pneumatic transfer system comprises aerated plastic shaped in such a manner as to hold a radioactive sample and aerated such that dissolution of the rabbit in a solvent followed by evaporation of the solid yields solid waste material having a volume significantly smaller than the original volume of the rabbit.

Dilatancy of Shear Transformations in a Colloidal Glass

NASA Astrophysics Data System (ADS)

Lu, Y. Z.; Jiang, M. Q.; Lu, X.; Qin, Z. X.; Huang, Y. J.; Shen, J.

2018-01-01

Shear transformations, as fundamental rearrangement events operating in local regions, hold the key of plastic flow of amorphous solids. Despite their importance, the dynamic features of shear transformations are far from clear, which is the focus of the present study. Here, we use a colloidal glass under shear as the prototype to directly observe the shear-transformation events in real space. By tracing the colloidal-particle rearrangements, we quantitatively determine two basic properties of shear transformations: local shear strain and dilatation (or free volume). It is revealed that the local free volume undergoes a significantly temporary increase prior to shear transformations, eventually leading to a jump of local shear strain. We clearly demonstrate that shear transformations have no memory of the initial free volume of local regions. Instead, their emergence strongly depends on the dilatancy ability of these local regions, i.e., the dynamic creation of free volume. More specifically, the particles processing the high dilatancy ability directly participate in subsequent shear transformations. These results experimentally enrich Argon's statement about the dilatancy nature of shear transformations and also shed insight into the structural origin of amorphous plasticity.

Study of thermite mixtures consolidated by cold gas dynamic spray process

NASA Astrophysics Data System (ADS)

Bacciochini, Antoine; Maines, Geoffrey; Poupart, Christian; Radulescu, Matei; Jodoin, Bertrand; Lee, Julian

2013-06-01

The present study focused on the cold gas dynamic spray process for manufacturing finely structured energetic materials with high reactivity, vanishing porosity, as well as structural integrity and arbitrary shape. The experiments have focused the reaction between the aluminum and metal oxides, such as Al-CuO and Al-MoO3 systems. To increase the reactivity, an initial mechanical activation was achieved through interrupted ball milling. The consolidation of the materials used the supersonic cold gas spray technique, where the particles are accelerated to high speeds and consolidated via plastic deformation upon impact, forming activated nano-composites in arbitrary shapes with close to zero porosity. This technique permits to retain the feedstock powder micro-structure and prevents any reactions during the consolidation phase. Reactivity of mixtures has been investigated through flame propagation analysis on cold sprayed samples and compacted powder mixture. Deflagration tests showed the influence of porosity on the reactivity.

Effect of nitric oxide, perfluorocarbon, and heliox on minute volume measurement and ventilator volumes delivered.

PubMed

Devabhaktuni, V G; Torres, A; Wilson, S; Yeh, M P

1999-08-01

To determine the effect of heliox, nitric oxide (NO), and perfluorocarbon on differential pressure pneumotachometer characteristics and to determine the effect of heliox on volumes delivered by the Siemens S900C (S900C), and Servo Ventilator 300 (SV300) ventilators. Prospective, laboratory study. Pulmonary laboratory of a tertiary care, nonprofit children's hospital. SV300, S900C ventilator, differential pressure pneumotachometer. Dual pneumotachometers were connected in series to a 0.5-L calibration syringe and a 1-L anesthesia bag creating a closed system. Calibration of the pneumotachometers was done in room air at ambient temperature with 100 strokes. Accepted accuracy of measured volumes is within 0.5%. Flow-conductance curves were constructed using 100 strokes each for heliox (70:30 mixture), NO, and perfluorocarbon. Expired gases of room air and a 70:30 mixture of heliox from the above ventilators were collected into a nondiffusing gas collection bag, and the volume was measured in a chain-compensated gasometer. Ten sets of 500-mL breaths (20 breaths each set) and 100-mL breaths (40 breaths each set) were collected. The paired Student's t-test was used to detect significant differences in measured volumes, with significance defined as p < .01. Volumes measured with the pneumotachometer using 25 ppm of NO, 50 ppm of NO, and perfluorocarbon were within +0.25%, -0.7%, and +0.4%, respectively (p = .155, p = .001, p = .06). Heliox decreased the conductance of the pneumotachometer, thereby increasing the measured volume by 15% (p < .001). However, heliox did not affect its linearity. Heliox had no affect on volumes delivered by the S900C. However, the SV300 delivered 7.9% less volume of heliox at a set tidal volume of 500 mL and 10.8% less at a set tidal volume of 100 mL. A 70:30 mixture of heliox caused a significantly overestimated gas volume measured and, therefore, an underestimated gas volume delivered by SV300. NO at 25 ppm and perfluorocarbon did not interfere with the accuracy of a differential pressure pneumotachometer. However, at 50 ppm, NO caused a difference in measured gas volume that was statistically, but not clinically, significant. Application of pneumotachometers in critically ill children receiving heliox requires recalibration. Heliox did not affect volumes delivered with the S900C ventilator. Although volumes delivered with the SV300 were significantly reduced by heliox, the difference can be corrected easily by increasing minute ventilation until expired tidal volume equals desired tidal volume.

METHOD 200.5 - DETERMINATION OF TRACE ELEMENTS IN DRINKING WATER BY AXIALLY VIEWED INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROMETRY

EPA Science Inventory

2.0 SUMMARY OF METHOD
2.1. A 50 mL aliquot of a well-mixed, non-filtered, acid preserved aqueous sample is accurately transferred to clean 50-mL plastic disposable digestion tube containing a mixture of nitric and hydrochloric acids. The aliquot is heated to 95 degrees C (+ o...

Biological resistance of polyethylene composites made with chemically modified fiber or flour

Treesearch

Rebecca E. Ibach; Craig M. Clemons

2002-01-01

The role of moisture in the biological decay of wood-plastic composites was investigated. Southern pine wood fiber and ponderosa pine wood flour were chemically modified using either acetic anhydride (AA), butylene oxide (BO), or propylene oxide (PO). A 50:50 mixture of high density polyethylene and either chemically modified fiber or flour, or untreated fiber or flour...

Time Neutron Technique for UXO Discrimination

DTIC Science & Technology

2010-12-01

mixture of TNT and RDX C-4 CFD Composition 4 military plastic explosive Constant Fraction Discriminator Cps CsI counts per second inorganic...Pdfs Probability Density Functions PET Positron Emission Tomography Pfa Probability of False Alarm PFTNA Pulsed Fast/Thermal Neutron Analysis PMTs...the ordnance type (rocket, mortar , projectile, etc.) and what filler material it contains (inert or empty), practice, HE, illumination, chemical (i.e

A Miniaturized Extruder to Prototype Amorphous Solid Dispersions: Selection of Plasticizers for Hot Melt Extrusion.

PubMed

Lauer, Matthias E; Maurer, Reto; Paepe, Anne T De; Stillhart, Cordula; Jacob, Laurence; James, Rajesh; Kojima, Yuki; Rietmann, Rene; Kissling, Tom; van den Ende, Joost A; Schwarz, Sabine; Grassmann, Olaf; Page, Susanne

2018-05-19

Hot-melt extrusion is an option to fabricate amorphous solid dispersions and to enhance oral bioavailability of poorly soluble compounds. The selection of suitable polymer carriers and processing aids determines the dissolution, homogeneity and stability performance of this solid dosage form. A miniaturized extrusion device (MinEx) was developed and Hypromellose acetate succinate type L (HPMCAS-L) based extrudates containing the model drugs neurokinin-1 (NK1) and cholesterylester transfer protein (CETP) were manufactured, plasticizers were added and their impact on dissolution and solid-state properties were assessed. Similar mixtures were manufactured with a lab-scale extruder, for face to face comparison. The properties of MinEx extrudates widely translated to those manufactured with a lab-scale extruder. Plasticizers, Polyethyleneglycol 4000 (PEG4000) and Poloxamer 188, were homogenously distributed but decreased the storage stability of the extrudates. Stearic acid was found condensed in ultrathin nanoplatelets which did not impact the storage stability of the system. Depending on their distribution and physicochemical properties, plasticizers can modulate storage stability and dissolution performance of extrudates. MinEx is a valuable prototyping-screening method and enables rational selection of plasticizers in a time and material sparing manner. In eight out of eight cases the properties of the extrudates translated to products manufactured in lab-scale extrusion trials.

Characterization of conducting cellulose acetate based polymer electrolytes doped with "green" ionic mixture.

PubMed

Ramesh, S; Shanti, R; Morris, Ezra

2013-01-02

Polymer electrolytes were developed by solution casting technique utilizing the materials of cellulose acetate (CA), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and deep eutectic solvent (DES). The DES is synthesized from the mixture of choline chloride and urea of 1:2 ratios. The increasing DES content well plasticizes the CA:LiTFSI:DES matrix and gradually improves the ionic conductivity and chemical integrity. The highest conducting sample was identified for the composition of CA:LiTFSI:DES (28 wt.%:12 wt.%:60 wt.%), which has the greatest ability to retain the room temperature ionic conductivity over the entire 30 days of storage time. The changes in FTIR cage peaks upon varying the DES content in CA:LiTFSI:DES prove the complexation. This complexation results in the collapse of CA matrix crystallinity, observed from the reduced intensity of XRD diffraction peaks. The DES-plasticized sample is found to be more heat-stable compared to pure CA. Nevertheless, the addition of DES diminishes the CA:LiTFSI matrix's heat-resistivity but at the minimum addition the thermal stability is enhanced. Copyright © 2012 Elsevier Ltd. All rights reserved.

Factors that influence the efficiency of a fluidized-bed-type tribo-electrostatic separator for mixed granular plastics

NASA Astrophysics Data System (ADS)

Dascalescu, L.; Fati, O.; Bilici, M.; Rahou, F.; Dragan, C.; Samuila, A.; Iuga, A.

2011-06-01

Fluidized bed devices have already been used as tribochargers for various industrial electrostatic separation processes. In the present paper, the authors investigate the behaviour of polyamide - polycarbonate granular plastic mixtures in a parallelepiped bed, the height of which is roughly 2 times its length or width, so that the collisions between granules become the prevailing tribocharging mechanism. Two of the opposite walls of the tribocharging chamber consist of metallic plates connected to two DC high-voltage supplies of opposite polarities, so that the charged particles are attracted to the electrodes and separated while still in the fluidized state. The collecting hoppers are designed as Faraday cups connected to two electrometers, thus allowing the instantaneous measurement of the charge carried by the separated particles. Experimental design methodology was employed for the optimization of the tribo-aero-electrostatic separation process, the input variables being the high-voltage applied to the electrodes and the duration of the tribocharging. Higher voltages applied to the electrode system do not necessarily lead to larger quantities of collected products but improve the purity of the concentrates. The composition of the mixture influences the outcome of the process.

Decreased contralateral breast volume after mastectomy, adjuvant chemotherapy, and anti-estrogen therapy, in particular in breasts with high density.

PubMed

Ishii, Naohiro; Ando, Jiro; Harao, Michiko; Takemae, Masaru; Kishi, Kazuo

2017-10-01

Adjuvant chemotherapy and anti-estrogenic therapy can result in decreased volume of the contralateral breast, following mastectomy for the treatment of breast cancer. However, no data on the effect of adjuvant therapy on contralateral breast volume have previously been reported. We aimed to evaluate the extent to which adjuvant therapy and differences in breast density contribute to decreased breast volume. We conducted a prospective cohort study, selecting 40 nonconsecutive patients who underwent immediate breast reconstruction with mastectomy and expander insertion followed by expander replacement. We measured the contralateral breast volume before each procedure. The extent of the change was analyzed with respect to adjuvant therapy and breast density measured by preoperative mammography. The greatest decrease in breast volume was 135.1 cm 3 . The decrease in breast volume was significantly larger in the adjuvant therapy (+) group, particularly in patients with high breast density, than in the adjuvant therapy (-) group. Significant differences between the chemotherapy (+), tamoxifen (+) group and the chemotherapy (-), tamoxifen (+) group were not found. Breast density scores had a range of 2.0-3.3 (mean: 2.8). In breast reconstruction, particularly when performed in one stage, preoperative mammography findings are valuable to plastic surgeons, and possible decreases in the contralateral breast volume due to adjuvant therapy, particularly in patients with high breast density, should be considered carefully. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Thermodynamic properties of model CdTe/CdSe mixtures

DOE PAGES

van Swol, Frank; Zhou, Xiaowang W.; Challa, Sivakumar R.; ...

2015-02-20

We report on the thermodynamic properties of binary compound mixtures of model groups II–VI semiconductors. We use the recently introduced Stillinger–Weber Hamiltonian to model binary mixtures of CdTe and CdSe. We use molecular dynamics simulations to calculate the volume and enthalpy of mixing as a function of mole fraction. The lattice parameter of the mixture closely follows Vegard's law: a linear relation. This implies that the excess volume is a cubic function of mole fraction. A connection is made with hard sphere models of mixed fcc and zincblende structures. We found that the potential energy exhibits a positive deviation frommore » ideal soluton behaviour; the excess enthalpy is nearly independent of temperatures studied (300 and 533 K) and is well described by a simple cubic function of the mole fraction. Using a regular solution approach (combining non-ideal behaviour for the enthalpy with ideal solution behaviour for the entropy of mixing), we arrive at the Gibbs free energy of the mixture. The Gibbs free energy results indicate that the CdTe and CdSe mixtures exhibit phase separation. The upper consolute temperature is found to be 335 K. Finally, we provide the surface energy as a function of composition. Moreover, it roughly follows ideal solution theory, but with a negative deviation (negative excess surface energy). This indicates that alloying increases the stability, even for nano-particles.« less

Plastic-bonded electrodes for nickel-cadmium accumulators. IV - Some specific problems of the positive active layer

NASA Astrophysics Data System (ADS)

Micka, K.; Mrha, J.; Klapste, B.

1980-06-01

The active layer of plastic-bonded nickel oxide electrodes undergoes expansion during discharging and contraction during charging; the latter however does not fully compensate for the expansion. These volume changes can be made reversible by the action of an external pressure. The electro-chemical behavior of the conductive components, carbon black and graphite, shows more or less severe corrosion during anodic current loading.

A Microscale Approach to Chemical Kinetics in the General Chemistry Laboratory: The Potassium Iodide Hydrogen Peroxide Iodine-Clock Reaction

ERIC Educational Resources Information Center

Sattsangi, Prem D.

2011-01-01

A microscale laboratory for teaching chemical kinetics utilizing the iodine clock reaction is described. Plastic pipets, 3 mL volume, are used to store and deliver precise drops of reagents and the reaction is run in a 24 well plastic tray using a total 60 drops of reagents. With this procedure, students determine the rate of reaction and the…

Estimation of packaged water consumption and associated plastic waste production from household budget surveys

NASA Astrophysics Data System (ADS)

Wardrop, Nicola A.; Dzodzomenyo, Mawuli; Aryeetey, Genevieve; Hill, Allan G.; Bain, Robert E. S.; Wright, Jim

2017-08-01

Packaged water consumption is growing in low- and middle-income countries, but the magnitude of this phenomenon and its environmental consequences remain unclear. This study aims to quantify both the volumes of packaged water consumed relative to household water requirements and associated plastic waste generated for three West African case study countries. Data from household expenditure surveys for Ghana, Nigeria and Liberia were used to estimate the volumes of packaged water consumed and thereby quantify plastic waste generated in households with and without solid waste disposal facilities. In Ghana, Nigeria and Liberia respectively, 11.3 (95% confidence interval: 10.3-12.4), 10.1 (7.5-12.5), and 0.38 (0.31-0.45) Ml day-1 of sachet water were consumed. This generated over 28 000 tonnes yr-1 of plastic waste, of which 20%, 63% and 57% was among households lacking formal waste disposal facilities in Ghana, Nigeria and Liberia respectively. Reported packaged water consumption provided sufficient water to meet daily household drinking-water requirements for 8.4%, less than 1% and 1.6% of households in Ghana, Nigeria and Liberia respectively. These findings quantify packaged water’s contribution to household water needs in our study countries, particularly Ghana, but indicate significant subsequent environmental repercussions.

A molecular dynamics approach for predicting the glass transition temperature and plasticization effect in amorphous pharmaceuticals.

PubMed

Gupta, Jasmine; Nunes, Cletus; Jonnalagadda, Sriramakamal

2013-11-04

The objectives of this study were as follows: (i) To develop an in silico technique, based on molecular dynamics (MD) simulations, to predict glass transition temperatures (Tg) of amorphous pharmaceuticals. (ii) To computationally study the effect of plasticizer on Tg. (iii) To investigate the intermolecular interactions using radial distribution function (RDF). Amorphous sucrose and water were selected as the model compound and plasticizer, respectively. MD simulations were performed using COMPASS force field and isothermal-isobaric ensembles. The specific volumes of amorphous cells were computed in the temperature range of 440-265 K. The characteristic "kink" observed in volume-temperature curves, in conjunction with regression analysis, defined the Tg. The MD computed Tg values were 367 K, 352 K and 343 K for amorphous sucrose containing 0%, 3% and 5% w/w water, respectively. The MD technique thus effectively simulated the plasticization effect of water; and the corresponding Tg values were in reasonable agreement with theoretical models and literature reports. The RDF measurements revealed strong hydrogen bond interactions between sucrose hydroxyl oxygens and water oxygen. Steric effects led to weak interactions between sucrose acetal oxygens and water oxygen. MD is thus a powerful predictive tool for probing temperature and water effects on the stability of amorphous systems during drug development.

A cell-centered Lagrangian finite volume approach for computing elasto-plastic response of solids in cylindrical axisymmetric geometries

NASA Astrophysics Data System (ADS)

Sambasivan, Shiv Kumar; Shashkov, Mikhail J.; Burton, Donald E.

2013-03-01

A finite volume cell-centered Lagrangian formulation is presented for solving large deformation problems in cylindrical axisymmetric geometries. Since solid materials can sustain significant shear deformation, evolution equations for stress and strain fields are solved in addition to mass, momentum and energy conservation laws. The total strain-rate realized in the material is split into an elastic and plastic response. The elastic and plastic components in turn are modeled using hypo-elastic theory. In accordance with the hypo-elastic model, a predictor-corrector algorithm is employed for evolving the deviatoric component of the stress tensor. A trial elastic deviatoric stress state is obtained by integrating a rate equation, cast in the form of an objective (Jaumann) derivative, based on Hooke's law. The dilatational response of the material is modeled using an equation of state of the Mie-Grüneisen form. The plastic deformation is accounted for via an iterative radial return algorithm constructed from the J2 von Mises yield condition. Several benchmark example problems with non-linear strain hardening and thermal softening yield models are presented. Extensive comparisons with representative Eulerian and Lagrangian hydrocodes in addition to analytical and experimental results are made to validate the current approach.

Internal short circuit and accelerated rate calorimetry tests of lithium-ion cells: Considerations for methane-air intrinsic safety and explosion proof/flameproof protection methods.

PubMed

Dubaniewicz, Thomas H; DuCarme, Joseph P

2016-09-01

Researchers with the National Institute for Occupational Safety and Health (NIOSH) studied the potential for lithium-ion cell thermal runaway from an internal short circuit in equipment for use in underground coal mines. In this third phase of the study, researchers compared plastic wedge crush-induced internal short circuit tests of selected lithium-ion cells within methane (CH 4 )-air mixtures with accelerated rate calorimetry tests of similar cells. Plastic wedge crush test results with metal oxide lithium-ion cells extracted from intrinsically safe evaluated equipment were mixed, with one cell model igniting the chamber atmosphere while another cell model did not. The two cells models exhibited different internal short circuit behaviors. A lithium iron phosphate (LiFePO 4 ) cell model was tolerant to crush-induced internal short circuits within CH 4 -air, tested under manufacturer recommended charging conditions. Accelerating rate calorimetry tests with similar cells within a nitrogen purged 353-mL chamber produced ignitions that exceeded explosion proof and flameproof enclosure minimum internal pressure design criteria. Ignition pressures within a 20-L chamber with 6.5% CH 4 -air were relatively low, with much larger head space volume and less adiabatic test conditions. The literature indicates that sizeable lithium thionyl chloride (LiSOCl 2 ) primary (non rechargeable) cell ignitions can be especially violent and toxic. Because ignition of an explosive atmosphere is expected within explosion proof or flameproof enclosures, there is a need to consider the potential for an internal explosive atmosphere ignition in combination with a lithium or lithium-ion battery thermal runaway process, and the resulting effects on the enclosure.

Modeling the measured effect of a nitroplasticizer (BDNPA/F) on cookoff of a plastic bonded explosive (PBX 9501)

DOE PAGES

Hobbs, Michael L.; Kaneshige, Michael J.; Erikson, William W.

2016-09-12

Here, we have used a modified version of the Sandia Instrumented Thermal Ignition (SITI) experiment to develop a pressure-dependent, five-step ignition model for a plastic bonded explosive (PBX 9501) consisting of 95 wt% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazoncine (HMX), 2.5 wt% Estane® 5703 (a polyurethane thermoplastic), and 2.5 wt% of a nitroplasticizer (NP): BDNPA/F, a 50/50 wt% eutectic mixture bis(2,2-dinitropropyl)-acetal (BDNPA) and bis(2,2-dinitropropyl)-formal (BDNPF). The five steps include desorption of water, decomposition of the NP to form NO2, reaction of the NO2 with Estane® and HMX, and decomposition of HMX. The model was fit using our experiments and successfully validated with experiments from fivemore » other laboratories with scales ranging from about 2 g to more than 2.5 kg of PBX. Our experimental variables included density, confinement, free gas volume, and temperature. We measured internal temperatures, confinement pressure, and ignition time. In some of our experiments, we used a borescope to visually observe the decomposing PBX. Our observations included the endothermic β–δ phase change of the HMX, a small exothermic temperature excursion in low-density unconfined experiments, and runaway ignition. We hypothesize that the temperature excursion in these low density experiments was associated with the NP decomposing exothermically within the PBX sample. This reactant-limited temperature excursion was not observed with our thermocouples in the high-density experiments. For these experiments, we believe the binder diffused to the edges of our high density samples and decomposed next to the highly conductive wall as confirmed by our borescope images.« less

Stability of extemporaneously prepared glycopyrrolate oral suspensions.

PubMed

Cober, Mary Petrea; Johnson, Cary E; Sudekum, David; Penprase, Kimberly

2011-05-01

The stability of extemporaneously prepared glycopyrrolate 0.5-mg/mL suspensions was evaluated. An oral suspension of glycopyrrolate 0.5 mg/mL was prepared by thoroughly grinding 30 1-mg tablets of glycopyrrolate in a glass mortar. Thirty milliliters of Ora-Plus and 30 mL of either Ora-Sweet or Ora-Sweet SF were mixed and added to the powder to make a final volume of 60 mL. Three identical samples of the formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and stored at room temperature (23-25 °C). A 1-mL sample was withdrawn from each of the three bottles with a micropipette immediately after preparation and 7, 15, 30, 60, and 90 days afterward. After further dilution to an expected concentration of 50 μg/mL with sample diluent, the samples were assayed in duplicate by stability-indicating high-performance liquid chromatography. The samples were visually examined for any color change and evaluated for pH on each day of analysis. Taste evaluations were performed at the beginning and end of the study. Stability was defined as the retention of at least 90% of the initial concentration. At least 95% of the initial glycopyrrolate remained throughout the 90-day study period in both preparations. There were no detectable changes in color, odor, taste, and pH, and no visible microbial growth was observed in any sample. Extemporaneously compounded suspensions of glycopyrrolate 0.5 mg/mL in a 1:1 mixture of Ora-Plus/Ora-Sweet or Ora-Plus/Ora-Sweet SF were stable for at least 90 days when stored in amber plastic bottles at room temperature.

Stability of an extemporaneously prepared tadalafil suspension.

PubMed

Pettit, Rebecca S; Johnson, Cary E; Caruthers, Regine L

2012-04-01

The stability of an extemporaneously prepared tadalafil oral suspension was studied. An oral suspension of tadalafil 5 mg/mL was prepared by thoroughly grinding 15 20-mg tadalafil tablets in a glass mortar. Thirty milliliters of Ora-Plus and 30 mL of Ora-Sweet were mixed and added to the powder to make a final volume of 60 mL. Three identical samples of the formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and stored at room temperature (23-25 °C). A 1-mL sample was withdrawn from each of the three bottles with a micropipette immediately after preparation and at 7, 14, 28, 57, and 91 days. After double dilution (1:10 and 0.1:5 v/v) to an expected concentration of 10 μg/mL with methanol and mobile phase, respectively, the samples were assayed in duplicate using stability-indicating high-performance liquid chromatography. The samples were visually examined for any color change and evaluated for pH changes on each day of analysis. Taste evaluation was performed at the beginning and end of the study. Stability was defined as the retention of at least 90% of the initial concentration. At least 99% of the initial tadalafil concentration remained throughout the 91-day study period. There were no detectable changes in color, odor, taste, and pH, and no visible microbial growth was observed in any sample. An extemporaneously prepared suspension of tadalafil 5 mg/mL in a 1:1 mixture of Ora-Plus and Ora-Sweet was stable for at least 91 days when stored in amber plastic bottles at room temperature.

Stability of extemporaneously prepared rifaximin oral suspensions.

PubMed

Cober, Mary Petrea; Johnson, Cary E; Lee, Jordan; Currie, Kenne

2010-02-15

The stability of extemporaneously prepared rifaximin oral suspensions was studied. An oral suspension of rifaximin 20 mg/mL was prepared by thoroughly grinding six 200-mg tablets of rifaximin in a glass mortar. Thirty milliliters of Ora-Plus and 30 mL of either Ora-Sweet or Ora-Sweet SF were mixed and added to the powder to make a final volume of 60 mL. Three identical samples of each formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and were stored at room temperature (23-25 degrees C). A 1-mL sample was withdrawn from each of the six bottles with a micropipette immediately after preparation and at 7, 15, 30, and 60 days. After further dilution to an expected concentration of 20 microg/mL with mobile phase, the samples were assayed in duplicate using stability-indicating high-performance liquid chromatography. The samples were visually examined for any color change and pH was tested on each day of analysis. Stability was determined by evaluating the percentage of the initial concentration remaining at each time point and defined as retention of at least 90% of the initial concentration of rifaximin. At least 99% of the initial rifaximin remained throughout the 60-day study period in both preparations. There were no detectable changes in color, odor, taste, or pH and no visible microbial growth in any sample. Extemporaneously prepared suspensions of rifaximin 20 mg/mL in 1:1 mixtures of Ora-Plus with either Ora-Sweet or Ora-Sweet SF were stable for at least 60 days when stored in 2-oz amber plastic bottles at room temperature.

Stability of extemporaneously prepared sodium phenylbutyrate oral suspensions.

PubMed

Caruthers, Regine L; Johnson, Cary E

2007-07-15

In an effort to minimize barriers to compliance and adherence and to improve the accuracy of dosage measurement, sugar-containing and sugar-free sodium phenylbutyrate suspensions were formulated, and the stability of these products over a 90-day period was determined. An oral suspension of sodium phenylbutyrate 200 mg/mL was prepared by thoroughly grinding 12 g of Sodium Phenylbutyrate Powder, USP, in a glass mortar. Thirty milliliters of Ora-Plus and 30 mL of either Ora-Sweet or Ora-Sweet SF were mixed and added to the powder to make a final volume of 60 mL. Three identical samples of each formulation were prepared and placed in 2-oz amber plastic bottles with child-resistant caps and were stored at room temperature. A 500-microL sample was withdrawn from each of the six bottles with a micropipette immediately after preparation and at 7, 14, 28, 60, and 90 days. After further dilution to an expected concentration of 100 microg/mL with the mobile phase, the samples were assayed by high-performance liquid chromatography. Stability was defined as the retention of at least 90% of the initial concentration. At least 95% of the initial sodium phenylbutyrate concentration remained throughout the 90-day study period in both preparations. There were no detectable changes in color, odor, taste, and pH and no visible microbial growth in any sample. Extemporaneously compounded suspensions of sodium phenylbutyrate, 200 mg/mL, in a 1:1 mixture of Ora-Plus and Ora-Sweet or Ora-Sweet SF were stable for at least 90 days when stored in 2-oz amber plastic bottles at room temperature.

Measurement of absolute concentrations of individual compounds in metabolite mixtures by gradient-selective time-zero 1H-13C HSQC with two concentration references and fast maximum likelihood reconstruction analysis.

PubMed

Hu, Kaifeng; Ellinger, James J; Chylla, Roger A; Markley, John L

2011-12-15

Time-zero 2D (13)C HSQC (HSQC(0)) spectroscopy offers advantages over traditional 2D NMR for quantitative analysis of solutions containing a mixture of compounds because the signal intensities are directly proportional to the concentrations of the constituents. The HSQC(0) spectrum is derived from a series of spectra collected with increasing repetition times within the basic HSQC block by extrapolating the repetition time to zero. Here we present an alternative approach to data collection, gradient-selective time-zero (1)H-(13)C HSQC(0) in combination with fast maximum likelihood reconstruction (FMLR) data analysis and the use of two concentration references for absolute concentration determination. Gradient-selective data acquisition results in cleaner spectra, and NMR data can be acquired in both constant-time and non-constant-time mode. Semiautomatic data analysis is supported by the FMLR approach, which is used to deconvolute the spectra and extract peak volumes. The peak volumes obtained from this analysis are converted to absolute concentrations by reference to the peak volumes of two internal reference compounds of known concentration: DSS (4,4-dimethyl-4-silapentane-1-sulfonic acid) at the low concentration limit (which also serves as chemical shift reference) and MES (2-(N-morpholino)ethanesulfonic acid) at the high concentration limit. The linear relationship between peak volumes and concentration is better defined with two references than with one, and the measured absolute concentrations of individual compounds in the mixture are more accurate. We compare results from semiautomated gsHSQC(0) with those obtained by the original manual phase-cycled HSQC(0) approach. The new approach is suitable for automatic metabolite profiling by simultaneous quantification of multiple metabolites in a complex mixture.

Keratin based bioplastic film from chicken feathers and its characterization.

PubMed

Ramakrishnan, Navina; Sharma, Swati; Gupta, Arun; Alashwal, Basma Yahya

2018-05-01

Plastics have been one of the highly valued materials and it plays an significant role in human's life such as in food packaging and biomedical applications. Bioplastic materials can gradually work as a substitute for various materials based on fossil oil. The issue like sustainability and environmental challenges which occur due to manufacturing and disposal of synthetic plastics can be conquering by bio-based plastics. Feathers are among the most inexpensive abundant, and renewable protein sources. Feathers disposal to the landfills leads to environmental pollutions and it results into wastage of 90% of protein raw material. Keratin is non-burning hydrophilic, and biodegradable due to which it can be applicable in various ways via chemical processing. Main objective of this research is to synthesis bioplastic using keratin from chicken feathers. Extracted keratin solution mixed with different concentration of glycerol (2 to 10%) to produce plastic films. The mixture was stirred under constant magnetic stirring at 60 °C for 5 h. The mixtures are then poured into aluminum weighing boat and dried in an oven at 60 °C for 24 h. The mechanical properties of the samples were tested and the physic-chemical properties of the bioplastic were studied. According to the results, Scanning Electron Microscopy test showed good compatible morphologies without holes, cavity and edge. The difference in chemical composition was analyzed using Fourier transform infrared spectroscopy (FTIR). The samples were also characterized by thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-Ray diffraction (XRD) to check the thermal and crystallinity properties. Other than that, bioplastic made up from keratin with 2% of glycerol has the best mechanical and thermal properties. According to biodegradability test, all bioplastic produced are proven biodegradable. Therefore, the results showed possible application of the film as an alternative to fossil oil based materials which are harmful to the environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Investigation on molecular interactions of binary mixtures of isobutanol with 1-alkanols (C1 - C6) at different temperatures. Application of the Peng-Robinson-Stryjek-Vera (PSRV) equation of state (EOS)

NASA Astrophysics Data System (ADS)

Khanlarzadeh, K.; Iloukhani, H.; Soleimani, M.

2017-07-01

Densities were measured for binary mixtures of isobutanol with 1-alkanols, namely: methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol and 1-hexanol at the temperatures of (288.15, 298.15 and 308.15) K and ambient pressure. Excess molar volumes, VmE , thermal expansion coefficients α, excess thermal expansion coefficients αE, and isothermal coefficients of pressure excess molar enthalpy, (∂HmE / ∂ P) T , x , were derived from the experimental data and the computed results were fitted to the Redlich-Kister equation. The Peng-Robinson-Stryjek-Vera (PRSV) equation of state was applied, in combination with simple mixing rules to predict the excess molar volume. The VmE results were positive for the mixtures of isobutanol with methanol, ethanol, 1-propanol, 1-butanol, and negative for isobutanol with 1-pentanol and 1-hexanol over the whole composition range. The results showed very small deviations from the behavior of ideal solutions in these mixtures and were analyzed to discuss the nature and strength of intermolecular interactions.

NASA Tech Briefs, May 2000. Volume 24, No. 5

NASA Technical Reports Server (NTRS)

2000-01-01

Topics include: Sensors: Test and Measurement; Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Composites and Plastics; Materials; Computer Programs; Mechanics;

Maternal exposure to a mixture of di(2-ethylhexyl) phthalate (DEHP) and polychlorinated biphenyls (PCBs) causes reproductive dysfunction in adult male mouse offspring.

PubMed

Fiandanese, Nadia; Borromeo, Vitaliano; Berrini, Anna; Fischer, Bernd; Schaedlich, Kristina; Schmidt, Juliane-Susanne; Secchi, Camillo; Pocar, Paola

2016-10-01

We investigated the effects of maternal exposure to the plasticizer di(2-ethylhexyl) phthalate (DEHP) and the organic industrial compounds polychlorinated biphenyls (PCBs), singly and combined, on the reproductive function of male mouse offspring. Mice dams were exposed throughout pregnancy and lactation to 1μg PCBs (101+118)/kg/day, 50μg DEHP/kg/day, or the DEHP/PCB mixture in the diet. The mixture induced permanent alterations in adult F1 males' reproductive health in a way, differently from the single compounds. Depending on the endpoint, we observed: (1) synergy in altering the gross and histological morphology of the testis; (2) antagonism on the expression levels of genes involved in pituitary-gonadal cross-talk; (3) non-interactions on sperm parameters and testosterone production. This study illustrates the complex action of a DEHP/PCB mixture, leading to a unique panel of effects on the male reproductive system, indicating the need for research on the reproductive hazards of combined endocrine disruptors. Copyright © 2016 Elsevier Inc. All rights reserved.

Low substrate temperature deposition of diamond coatings derived from glassy carbon

DOEpatents

Holcombe, C.E. Jr.; Seals, R.D.

1995-09-26

A process is disclosed for depositing a diamond coating on a substrate at temperatures less than about 550 C. A powder mixture of glassy carbon and diamond particles is passed through a high velocity oxy-flame apparatus whereupon the powders are heated prior to impingement at high velocity against the substrate. The powder mixture contains between 5 and 50 powder volume percent of the diamond particles, and preferably between 5 and 15 powder volume percent. The particles have a size from about 5 to about 100 micrometers, with the diamond particles being about 5 to about 30 micrometers. The flame of the apparatus provides a velocity of about 350 to about 1000 meters per second, with the result that upon impingement upon the substrate, the glassy carbon is phase transformed to diamond as coaxed by the diamond content of the powder mixture. 2 figs.

Activity coefficients from molecular simulations using the OPAS method

NASA Astrophysics Data System (ADS)

Kohns, Maximilian; Horsch, Martin; Hasse, Hans

2017-10-01

A method for determining activity coefficients by molecular dynamics simulations is presented. It is an extension of the OPAS (osmotic pressure for the activity of the solvent) method in previous work for studying the solvent activity in electrolyte solutions. That method is extended here to study activities of all components in mixtures of molecular species. As an example, activity coefficients in liquid mixtures of water and methanol are calculated for 298.15 K and 323.15 K at 1 bar using molecular models from the literature. These dense and strongly interacting mixtures pose a significant challenge to existing methods for determining activity coefficients by molecular simulation. It is shown that the new method yields accurate results for the activity coefficients which are in agreement with results obtained with a thermodynamic integration technique. As the partial molar volumes are needed in the proposed method, the molar excess volume of the system water + methanol is also investigated.

Low substrate temperature deposition of diamond coatings derived from glassy carbon

DOEpatents

Holcombe, Jr., Cressie E.; Seals, Roland D.

1995-01-01

A process for depositing a diamond coating on a substrate at temperatures less than about 550.degree. C. A powder mixture of glassy carbon and diamond particles is passed through a high velocity oxy-flame apparatus whereupon the powders are heated prior to impingement at high velocity against the substrate. The powder mixture contains between 5 and 50 powder volume percent of the diamond particles, and preferably between 5 and 15 powder volume percent. The particles have a size from about 5 to about 100 micrometers, with the diamond particles being about 5 to about 30 micrometers. The flame of the apparatus provides a velocity of about 350 to about 1000 meters per second, with the result that upon impingement upon the substrate, the glassy carbon is phase transformed to diamond as coaxed by the diamond content of the powder mixture.

Water structure in polyethylene glycols for preservation of wooden artefacts. A NIR-FT-Raman spectroscopic investigation

NASA Astrophysics Data System (ADS)

Christensen, M.; Nielsen, O. F.; Jensen, P.; Schnell, U.

2005-02-01

The interaction between polyethylene glycol (PEG) and water in mixtures has been investigated with a particular emphasis on the existence of 'free' water with a tetragonal bulk-like water structure. PEG is used in museum preservation of wooden objects, where free water must be avoided due to the danger of further microbial growth, contractile capillary forces and aqueous transport in wooden archaeological artefacts. A NIR-FT-Raman instrument with excitation at 1064 nm was used for this investigation. The OH stretch region around 3200 cm-1 shows changes in intensity with changing water content and the R(νbar)-function was applied in order to observe free water in the 100-300 cm-1 region. Mixtures of PEG and water were investigated with water contents ranging from 0 to 90% volume. It was found that free water appears around 28-32% volume in a PEG 600 mixture.

Study of intermolecular interactions in binary mixtures of 2'-chloro-4-methoxy-3-nitro benzil in various solvents and at different concentrations by the measurement of acoustic properties.

PubMed

Nithya, G; Thanuja, B; Kanagam, Charles C

2013-01-01

Density (ρ), ultrasonic velocity (u), adiabatic compressibility (β), apparent molar volume (Ø), acoustic impedance (Z), intermolecular free length (L(f)), relative association (RA) of binary mixtures of 2'-chloro-4-methoxy-3-nitro benzil (abbreviated as 2CBe) in ethanol, acetonitrile, chloroform, dioxane and benzene were measured at different concentrations at 298 K. Several useful parameters such as excess density, excess ultrasonic velocity, excess adiabatic compressibility, excess apparent molar volume, excess acoustic impedance and excess intermolecular free length have been calculated. These parameters are used to explain the nature of intermolecular interactions taking place in the binary mixture. The above study is useful in understanding the solute--solvent interactions occurring in different concentrations at room temperature. Copyright © 2012 Elsevier B.V. All rights reserved.

In vitro formation and thermal transition of novel hybrid fibrils from type I fish scale collagen and type I porcine collagen

NASA Astrophysics Data System (ADS)

Chen, Song; Ikoma, Toshiyuki; Ogawa, Nobuhiro; Migita, Satoshi; Kobayashi, Hisatoshi; Hanagata, Nobutaka

2010-06-01

Novel type I collagen hybrid fibrils were fabricated by neutralizing a mixture of type I fish scale collagen solution and type I porcine collagen solution with a phosphate buffer saline at 28 °C. Their structure was discussed in terms of the volume ratio of fish/porcine collagen solution. Scanning electron and atomic force micrographs showed that the diameter of collagen fibrils derived from the collagen mixture was larger than those derived from each collagen, and all resultant fibrils exhibited a typical D-periodic unit of ~67 nm, irrespective of volume ratio of both collagens. Differential scanning calorimetry revealed only one endothermic peak for the fibrils derived from collagen mixture or from each collagen solution, indicating that the resultant collagen fibrils were hybrids of type I fish scale collagen and type I porcine collagen.

A critical analysis of the biological impacts of plasticizers on wildlife

PubMed Central

Oehlmann, Jörg; Schulte-Oehlmann, Ulrike; Kloas, Werner; Jagnytsch, Oana; Lutz, Ilka; Kusk, Kresten O.; Wollenberger, Leah; Santos, Eduarda M.; Paull, Gregory C.; Van Look, Katrien J. W.; Tyler, Charles R.

2009-01-01

This review provides a critical analysis of the biological effects of the most widely used plasticizers, including dibutyl phthalate, diethylhexyl phthalate, dimethyl phthalate, butyl benzyl phthalate and bisphenol A (BPA), on wildlife, with a focus on annelids (both aquatic and terrestrial), molluscs, crustaceans, insects, fish and amphibians. Moreover, the paper provides novel data on the biological effects of some of these plasticizers in invertebrates, fish and amphibians. Phthalates and BPA have been shown to affect reproduction in all studied animal groups, to impair development in crustaceans and amphibians and to induce genetic aberrations. Molluscs, crustaceans and amphibians appear to be especially sensitive to these compounds, and biological effects are observed at environmentally relevant exposures in the low ng l−1 to µg l−1 range. In contrast, most effects in fish (except for disturbance in spermatogenesis) occur at higher concentrations. Most plasticizers appear to act by interfering with the functioning of various hormone systems, but some phthalates have wider pathways of disruption. Effect concentrations of plasticizers in laboratory experiments coincide with measured environmental concentrations, and thus there is a very real potential for effects of these chemicals on some wildlife populations. The most striking gaps in our current knowledge on the impacts of plasticizers on wildlife are the lack of data for long-term exposures to environmentally relevant concentrations and their ecotoxicity when part of complex mixtures. Furthermore, the hazard of plasticizers has been investigated in annelids, molluscs and arthropods only, and given the sensitivity of some invertebrates, effects assessments are warranted in other invertebrate phyla. PMID:19528055

76 FR 41371 - Impact of Reducing the Mixture Concentration Threshold for Commercial Schedule 3 Chemical...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-13

...The Bureau of Industry and Security (BIS) is seeking public comments on the impact of amending the Chemical Weapons Convention Regulations (CWCR) to reduce the concentration level at which the CWCR exempt certain mixtures containing Schedule 3 chemicals from the declaration requirements that apply to Schedule 3 chemical production and the reporting requirements that apply to exports and imports of Schedule 3 chemicals under the Chemical Weapons Convention (CWC). BIS is considering amending the CWCR declaration requirements that apply to the production of Schedule 3 chemicals to conform with the low concentration exemption adopted by the Organization for the Prohibition of Chemical Weapons (OPCW) in 2003, which applies when the concentration of any single Schedule 3 chemical in a mixture is ``30% or less,'' by weight or volume (whichever yields the lesser percent). Currently, the CWCR do not require the quantity of a Schedule 3 chemical contained in a mixture to be counted for declaration or reporting purposes if the concentration of the Schedule 3 chemical in the mixture is ``less than 80%'' by volume or weight (whichever yields the lesser percent). The current low concentration level was implemented in accordance with requirements set forth in the Chemical Weapons Convention Implementation Act (CWCIA). Accordingly, publication and implementation of regulatory changes affecting this low concentration exemption level would be contingent upon amendment of the CWCIA by the Congress. In addition, consistent with U.S. national discretion, BIS is considering amending the CWCR reporting requirements for exports and imports of Schedule 3 chemicals by reducing the low concentration exemption that applies to certain mixtures containing Schedule 3 chemicals from the current low concentration level of ``less than 80%'' of a Schedule 3 chemical by volume or weight (whichever yields the lesser percent) to a concentration of ``30% or less.''

Development of a Plastic Melt Waste Compactor for Space Missions Experiments and Prototype Design

NASA Technical Reports Server (NTRS)

Pace, Gregory; Wignarajah, Kanapathipillai; Pisharody, Suresh; Fisher, John

2004-01-01

This paper describes development at NASA Ames Research Center of a heat melt compactor that can be used on both near term and far term missions. Experiments have been performed to characterize the behavior of composite wastes that are representative of the types of wastes produced on current and previous space missions such as International Space Station, Space Shuttle, MIR and Skylab. Experiments were conducted to characterize the volume reduction, bonding, encapsulation and biological stability of the waste composite and also to investigate other key design issues such as plastic extrusion, noxious off-gassing and removal of the of the plastic waste product from the processor. The experiments provided the data needed to design a prototype plastic melt waste processor, a description of which is included in the paper.

Physicochemical Properties of Glycine-Based Ionic Liquid [QuatGly-OEt][EtOSO3] (2-Ethoxy-1-ethyl-1,1-dimethyl-2-oxoethanaminium ethyl sulfate) and Its Binary Mixtures with Poly(ethylene glycol) (Mw = 200) at Various Temperatures

PubMed Central

Wu, Tzi-Yi; Chen, Bor-Kuan; Hao, Lin; Lin, Yuan-Chung; Wang, H. Paul; Kuo, Chung-Wen; Sun, I-Wen

2011-01-01

This work includes specific basic characterization of synthesized glycine-based Ionic Liquid (IL) [QuatGly-OEt][EtOSO3] by NMR, elementary analysis and water content. Thermophysical properties such as density, ρ, viscosity, η, refractive index, n, and conductivity, κ, for the binary mixture of [QuatGly-OEt][EtOSO3] with poly(ethylene glycol) (PEG) [Mw = 200] are measured over the whole composition range. The temperature dependence of density and dynamic viscosity for neat [QuatGly-OEt][EtOSO3] and its binary mixture can be described by an empirical polynomial equation and by the Vogel-Tammann-Fucher (VTF) equation, respectively. The thermal expansion coefficient of the ILs is ascertained using the experimental density results, and the excess volume expansivity is evaluated. The negative values of excess molar volume for the mixture indicate the ion-dipole interactions and packing between IL and PEG oligomer. The results of binary excess property (VmE ) and deviations (Δη, Δxn, ΔΨn, ΔxR, and ΔΨR) are discussed in terms of molecular interactions and molecular structures in the binary mixture. PMID:22272102

Viscous slip coefficients for binary gas mixtures measured from mass flow rates through a single microtube

NASA Astrophysics Data System (ADS)

Yamaguchi, H.; Takamori, K.; Perrier, P.; Graur, I.; Matsuda, Y.; Niimi, T.

2016-09-01

The viscous slip coefficient for helium-argon binary gas mixture is extracted from the experimental values of the mass flow rate through a microtube. The mass flow rate is measured by the constant-volume method. The viscous slip coefficient was obtained by identifying the measured mass flow rate through a microtube with the corresponding analytical expression, which is a function of the Knudsen number. The measurements were carried out in the slip flow regime where the first-order slip boundary condition can be applied. The measured viscous slip coefficients of binary gas mixtures exhibit a concave function of the molar ratio of the mixture, showing a similar profile with numerical results. However, from the detailed comparison between the measured and numerical values with the complete and incomplete accommodation at a surface, it is inappropriate to estimate the viscous slip coefficient for the mixture numerically by employing separately measured tangential momentum accommodation coefficient for each component. The time variation of the molar ratio in the downstream chamber was measured by sampling the gas from the chamber using the quadrupole mass spectrometer. In our measurements, it is indicated that the volume flow rate of argon is larger than that of helium because of the difference in the tangential momentum accommodation coefficient.

Phase equilibria computations of multicomponent mixtures at specified internal energy and volume

NASA Astrophysics Data System (ADS)

Myint, Philip C.; Nichols, Albert L., III; Springer, H. Keo

2017-06-01

Hydrodynamic simulation codes for high-energy density science applications often use internal energy and volume as their working variables. As a result, the codes must determine the thermodynamic state that corresponds to the specified energy and volume by finding the global maximum in entropy. This task is referred to as the isoenergetic-isochoric flash. Solving it for multicomponent mixtures is difficult because one must find not only the temperature and pressure consistent with the energy and volume, but also the number of phases present and the composition of the phases. The few studies on isoenergetic-isochoric flash that currently exist all require the evaluation of many derivatives that can be tedious to implement. We present an alternative approach that is based on a derivative-free method: particle swarm optimization. The global entropy maximum is found by running several instances of particle swarm optimization over different sets of randomly selected points in the search space. For verification, we compare the predicted temperature and pressure to results from the related, but simpler problem of isothermal-isobaric flash. All of our examples involve the equation of state we have recently developed for multiphase mixtures of the energetic materials HMX, RDX, and TNT. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Bio-inspired digital signal processing for fast radionuclide mixture identification

NASA Astrophysics Data System (ADS)

Thevenin, M.; Bichler, O.; Thiam, C.; Bobin, C.; Lourenço, V.

2015-05-01

Countries are trying to equip their public transportation infrastructure with fixed radiation portals and detectors to detect radiological threat. Current works usually focus on neutron detection, which could be useless in the case of dirty bomb that would not use fissile material. Another approach, such as gamma dose rate variation monitoring is a good indication of the presence of radionuclide. However, some legitimate products emit large quantities of natural gamma rays; environment also emits gamma rays naturally. They can lead to false detections. Moreover, such radio-activity could be used to hide a threat such as material to make a dirty bomb. Consequently, radionuclide identification is a requirement and is traditionally performed by gamma spectrometry using unique spectral signature of each radionuclide. These approaches require high-resolution detectors, sufficient integration time to get enough statistics and large computing capacities for data analysis. High-resolution detectors are fragile and costly, making them bad candidates for large scale homeland security applications. Plastic scintillator and NaI detectors fit with such applications but their resolution makes identification difficult, especially radionuclides mixes. This paper proposes an original signal processing strategy based on artificial spiking neural networks to enable fast radionuclide identification at low count rate and for mixture. It presents results obtained for different challenging mixtures of radionuclides using a NaI scintillator. Results show that a correct identification is performed with less than hundred counts and no false identification is reported, enabling quick identification of a moving threat in a public transportation. Further work will focus on using plastic scintillators.

Studies of Partial Molar Volumes of Some Narcotic-Analgesic Drugs in Aqueous-Alcoholic Mixtures at 25°C

NASA Astrophysics Data System (ADS)

Sharma, Poonam; Chauhan, S.; Syal, V. K.; Chauhan, M. S.

2008-04-01

Partial molar volumes of the drugs Parvon Spas, Parvon Forte, Tramacip, and Parvodex in aqueous mixtures of methanol (MeOH), ethanol (EtOH), and propan-1-ol (1-PrOH) have been determined. The data have been evaluated using the Masson equation. The parameters, apparent molar volumes {(φ_v)}, partial molar volumes {(φ_v0)}, and S v values (experimental slopes) have been interpreted in terms of solute solvent interactions. In addition, these studies have also been extended to determine the effect of these drugs on the solvation behavior of an electrolyte (sodium chloride), a surfactant (sodium dodecyl sulfate), and a non-electrolyte (sucrose). It can be inferred from these studies that all drug cations can be regarded as structure makers/promoters due to hydrophobic hydration. Furthermore, the results are correlated to understand the solution behavior of drugs in aqueous-alcoholic systems, as a function of the nature of the alcohol and solutes.

Volumetric analysis of cerebellum in short-track speed skating players.

PubMed

Park, In Sung; Lee, Nam Joon; Kim, Tae-Young; Park, Jin-Hoon; Won, Yu-Mi; Jung, Yong-Ju; Yoon, Jin-Hwan; Rhyu, Im Joo

2012-12-01

The cerebellum is associated with balance control and coordination, which might be important for gliding on smooth ice at high speeds. A number of case studies have shown that cerebellar damage induces impaired balance and coordination. As a positive model, therefore, we investigated whether plastic changes in the volumes of cerebellar subregions occur in short-track speed skating players who must have extraordinary abilities of balance and coordination, using three-dimensional magnetic resonance imaging volumetry. The manual tracing was performed and the volumes of cerebellar hemisphere and vermian lobules were compared between short-track speed skating players (n=16) and matched healthy controls (n=18). We found larger right cerebellar hemisphere volume and vermian lobules VI-VII (declive, folium, and tuber) in short-track speed skating players in comparison with the matched controls. The finding suggests that the specialized abilities of balance and coordination are associated with structural plasticity of the right hemisphere of cerebellum and vermian VI-VII and these regions play an essential role in balance and coordination.

Prediction of soil stress-strain response incorporates mobilised shear strength envelope of granitic residual soil

NASA Astrophysics Data System (ADS)

Rahman, Abdul Samad Abdul; Noor, Mohd Jamaludin Md; Ahmad, Juhaizad Bin; Sidek, Norbaya

2017-10-01

The concept of effective stress has been the principal concept in characterizing soil volume change behavior in soil mechanics, the settlement models developed using this concept have been empirical in nature. However, there remain certain unexplained soil volume change behaviors that cannot be explained using the effective stress concept, one such behaviour is the inundation settlement. Studies have begun to indicate the inevitable role of shear strength as a critical element to be incorporated in models to unravel the unexplained soil behaviours. One soil volume change model that applies the concept of effective stress and the shear strength interaction is the Rotational Multiple Yield Surface Framework (RMYSF) model. This model has been developed from the soil-strain behavior under anisotropic stress condition. Hence, the RMYSF actually measure the soil actual elasto-plastic response to stress rather than assuming it to be fully elastic or plastic as normally perceived by the industry. The frameworks measures the increase in the mobilize shear strength when the soil undergo anisotropic settlement.

Dissipative particle dynamics parameterization and simulations to predict negative volume excess and structure of PEG and water mixtures

NASA Astrophysics Data System (ADS)

Kacar, Gokhan

2017-12-01

We report the results of dissipative particle dynamics (DPD) parameterization and simulations of a mixture of hydrophilic polymer, PEG 400, and water which are known to exhibit negative volume excess property upon mixing. The addition of a Morse potential to the conventional DPD potential mimics the hydrogen bond attraction, where the parameterization takes the internal chemistry of the beads into account. The results indicate that the mixing of PEG and water are maintained by the influence of hydrogen bonds, and the mesoscopic structure is characterized by the trade-off of enthalpic and entropic effects.

Physicochemical properties of binary solutions of propylene carbonate-acetonitrile in the range of 253.15-313.15 K

NASA Astrophysics Data System (ADS)

Tyunina, E. Yu.; Chekunova, M. D.

2017-05-01

The density, dynamic viscosity, and dielectric constant of propylene carbonate solutions with acetonitrile are measured over the composition of a mixed solvent at temperatures of 253.15, 273.15, 293.15, and 313.15 K. The molar volume, molar viscosity, and molar capacity of a mixture of propylene carbonate-acetonitrile and an excess amount of it are calculated. The effect the temperature and composition of the mixture have on the excess molar properties is discussed. A linear correlation is observed between the values of the molar fluidity, capacity, polarization, and molar volume of the studied system.

From Modeling of Plasticity in Single-Crystal Superalloys to High-Resolution X-rays Three-Crystal Diffractometer Peaks Simulation

NASA Astrophysics Data System (ADS)

Jacques, Alain

2016-12-01

The dislocation-based modeling of the high-temperature creep of two-phased single-crystal superalloys requires input data beyond strain vs time curves. This may be obtained by use of in situ experiments combining high-temperature creep tests with high-resolution synchrotron three-crystal diffractometry. Such tests give access to changes in phase volume fractions and to the average components of the stress tensor in each phase as well as the plastic strain of each phase. Further progress may be obtained by a new method making intensive use of the Fast Fourier Transform, and first modeling the behavior of a representative volume of material (stress fields, plastic strain, dislocation densities…), then simulating directly the corresponding diffraction peaks, taking into account the displacement field within the material, chemical variations, and beam coherence. Initial tests indicate that the simulated peak shapes are close to the experimental ones and are quite sensitive to the details of the microstructure and to dislocation densities at interfaces and within the soft γ phase.

Primary combination of phase-field and discrete dislocation dynamics methods for investigating athermal plastic deformation in various realistic Ni-base single crystal superalloy microstructures

NASA Astrophysics Data System (ADS)

Gao, Siwen; Rajendran, Mohan Kumar; Fivel, Marc; Ma, Anxin; Shchyglo, Oleg; Hartmaier, Alexander; Steinbach, Ingo

2015-10-01

Three-dimensional discrete dislocation dynamics (DDD) simulations in combination with the phase-field method are performed to investigate the influence of different realistic Ni-base single crystal superalloy microstructures with the same volume fraction of {γ\\prime} precipitates on plastic deformation at room temperature. The phase-field method is used to generate realistic microstructures as the boundary conditions for DDD simulations in which a constant high uniaxial tensile load is applied along different crystallographic directions. In addition, the lattice mismatch between the γ and {γ\\prime} phases is taken into account as a source of internal stresses. Due to the high antiphase boundary energy and the rare formation of superdislocations, precipitate cutting is not observed in the present simulations. Therefore, the plastic deformation is mainly caused by dislocation motion in γ matrix channels. From a comparison of the macroscopic mechanical response and the dislocation evolution for different microstructures in each loading direction, we found that, for a given {γ\\prime} phase volume fraction, the optimal microstructure should possess narrow and homogeneous γ matrix channels.

A Constitutive Model for Strain-Controlled Strength Degradation of Rockmasses (SDR)

NASA Astrophysics Data System (ADS)

Kalos, A.; Kavvadas, M.

2017-11-01

The paper describes a continuum, rate-independent, incremental plasticity constitutive model applicable in weak rocks and heavily fractured rockmasses, where mechanical behaviour is controlled by rockmass strength rather than structural features (discontinuities). The model describes rockmass structure by a generalised Hoek-Brown Structure Envelope (SE) in the stress space. Stress paths inside the SE are nonlinear and irreversible to better simulate behaviour at strains up to peak strength and under stress reversals. Stress paths on the SE have user-controlled volume dilatancy (gradually reducing to zero at large shear strains) and can model post-peak strain softening of brittle rockmasses via a structure degradation (damage) mechanism triggered by accumulated plastic shear strains. As the SE may strain harden with plastic strains, ductile behaviour can also be modelled. The model was implemented in the Finite Element Code Simulia ABAQUS and was applied in plane strain (2D) excavation of a cylindrical cavity (tunnel) to predict convergence-confinement curves. It is shown that small-strain nonlinearity, variable volume dilatancy and post-peak hardening/softening strongly affect the predicted curves, resulting in corresponding differences of lining pressures in real tunnel excavations.

Modeling the interaction of binary and ternary mixtures of estradiol and bisphenol A or its analogues in an in vitro estrogen mediated transcriptional activation assay (T47D-KBlue).

EPA Science Inventory

Bisphenol A is a ubiquitous monomer used to manufacture polycarbonate plastics. Exposure ofhuman and wildlife populations to bisphenol A and its analogs is widespread and well documented. Bisphenol A is hypothesized to be estrogenic in both in vivo and in vitro studies and has be...

Ariel 6 measurements of ultra-heavy cosmic ray fluxes in the region 34 or = Z or = 48

NASA Technical Reports Server (NTRS)

Fowler, P. H.; Masheder, M. R. W.; Moses, R. T.; Walker, R. N. F.; Worley, A.; Gay, A. M.

1985-01-01

The Ariel VI satellite was launched by NASA on a Scout rocket on 3rd June 1979 from Wallops Island, Virginia, USA, into a near circular 625 km orbit inclined at 55 deg. It carried a spherical cosmic ray detector designed by a group from Bristol University. A spherical aluminum vessel of diameter 75 cm contains a gas scintillation mixture and a thin spherical shell of Pilot 425 plastic, and forms a single optical cavity viewed by 16 photomultipliers. Particle tracks through the detector may be characterized by their impact parameter p and by whether or not they pass through the cup of plastic scintillator placed between the sphere and the spacecraft body (referred to below as the Anti-Coincidence Detector or ACD). Individual particle charges are determined by separately measuring the gas scintillation and the Cerenkov emission from the plastic shell. This is possible because of the quite different distribution in time of these emissions.

Killing of Campylobacter on contaminated plastic and wooden cutting boards by glycerol monocaprate (monocaprin).

PubMed

Thormar, H; Hilmarsson, H

2010-09-01

Contamination in the kitchen with foodborne bacteria is a risk factor in human exposure to these pathogens, an important route being transfer of bacteria from contaminated cutting boards and other surfaces to humans. The aim of this study was to test microbicidal emulsions of glycerol monocaprate (monocaprin) against Campylobacter on contaminated cutting boards. Plastic and wooden cutting boards, soiled with meat juice heavily contaminated with Campylobacter, were treated for 2 min with emulsions of monocaprin (MC) made in water or in buffer at low pH. Viable Campylobacter counts were reduced below the detectable level on plastic board surfaces after treatment with MC emulsions with or without 1.25% washing-up liquids (WUL). The counts were also greatly reduced on wooden boards (P < 0.05). Monocaprin emulsions and mixtures of MC emulsions and WUL may be useful as sanitizers/disinfectants in kitchens and in other food preparing and processing facilities. Cleaning with MC emulsions with or without WUL may reduce the risk of human exposure to Campylobacter.

Assessing the safety of co-exposure to food packaging migrants in food and water using the maximum cumulative ratio and an established decision tree.

PubMed

Price, Paul; Zaleski, Rosemary; Hollnagel, Heli; Ketelslegers, Hans; Han, Xianglu

2014-01-01

Food contact materials can release low levels of multiple chemicals (migrants) into foods and beverages, to which individuals can be exposed through food consumption. This paper investigates the potential for non-carcinogenic effects from exposure to multiple migrants using the Cefic Mixtures Ad hoc Team (MIAT) decision tree. The purpose of the assessment is to demonstrate how the decision tree can be applied to concurrent exposures to multiple migrants using either hazard or structural data on the specific components, i.e. based on the acceptable daily intake (ADI) or the threshold of toxicological concern. The tree was used to assess risks from co-exposure to migrants reported in a study on non-intentionally added substances (NIAS) eluting from food contact-grade plastic and two studies of water bottles: one on organic compounds and the other on ionic forms of various elements. The MIAT decision tree assigns co-exposures to different risk management groups (I, II, IIIA and IIIB) based on the hazard index, and the maximum cumulative ratio (MCR). The predicted co-exposures for all examples fell into Group II (low toxicological concern) and had MCR values of 1.3 and 2.4 (indicating that one or two components drove the majority of the mixture's toxicity). MCR values from the study of inorganic ions (126 mixtures) ranged from 1.1 to 3.8 for glass and from 1.1 to 5.0 for plastic containers. The MCR values indicated that a single compound drove toxicity in 58% of the mixtures. MCR values also declined with increases in the hazard index for the screening assessments of exposure (suggesting fewer substances contributed as risk potential increased). Overall, it can be concluded that the data on co-exposure to migrants evaluated in these case studies are of low toxicological concern and the safety assessment approach described in this paper was shown to be a helpful screening tool.

Clay Stabilization Using the Ash of Mount Sinabung in Terms of the Value of California Bearing Ratio (CBR)

NASA Astrophysics Data System (ADS)

Hastuty, I. P.; Roesyanto, R.; Napitupulu, S. M. A.

2018-02-01

Most areas in Indonesia consist of clay soils with high plasticity so that to meet technical requirements the soil needs improvement, which is known as soil stabilization.There are three ways of soil stabilization process, i.e. mechanical, physical and chemical. In this study, chemical stabilization was performed, that was by adding stabilizing agents to the soil. The stabilizing agent used was the ash of Mount Sinabung. Since 2010 until now, Sinabung Mountain is still experiencing eruption that produces a lot of volcanic ash and it inconveniences the environment. So, it is expected that this research will be able to optimize the utilization of Sinabung ash. The purpose of this study was to investigate the effect of the addition of Mount Sinabung ash to CBR (California Bearing Ratio) value, to determine the effect of the curing time of one day and fourteen days mixture on the CBR value, and to find the mixed content with effective curing time to produce the largest CBR value. Based on this study, the soil type CL (Clay - Low Plasticity) was obtained, based on the classification of USCS (Unified Soil Classification System) and categorized as A-6 (6) based on the classification of AASHTO (American Association of State Highway and Transportation officials) with the most effective mixed stabilizer material which was the variation of 10% Mount Sinabung ash with fourteen days of curing time. The CBR value resulted from the mixture of 10% Sinabung ash that was cured within fourteen days was 8.95%. By the increase of the content of the Sinabung ash, the CBR value always improved to the level of 10%, Sinabung ash then decreased and became constant at the mixture of higher volcanic ash mixture but remained above the CBR value of the original soil.

Stability of Hydromorphone-Ketamine Solutions in Glass Bottles, Plastic Syringes, and IV Bags for Pediatric Use.

PubMed

Ensom, Mary H H; Decarie, Diane; Leung, Karen; Montgomery, Carolyne

2009-03-01

To evaluate the stability of mixtures of hydromorphone and ketamine in 0.9% sodium chloride (normal saline [NS]) after storage for up to 7 days at room temperature (25°C). The stability of 3 standard mixtures of hydromorphone and ketamine (hydromorphone 0.2 mg/mL + ketamine 0.2 mg/mL, hydromorphone 0.2 mg/mL + ketamine 0.6 mg/mL, and hydromorphone 0.2 mg/mL + ketamine 1.0 mg/mL) in NS was studied. Portions of each mixture were transferred to 3 brown glass bottles (100 mL), 3 plastic syringes (50 mL), and 3 IV bags (50 mL), which were then stored at room temperature (25°C). Physical characteristics, including pH, colour, and precipitation, were evaluated daily. Three 1.5-mL samples were collected from each bottle, syringe, and IV bag at baseline, at 24, 48, and 72 hours, and on day 7. Samples were analyzed in triplicate by a stability-indicating high-performance liquid chromatography method. Solutions were considered stable if they maintained 90% of the initial concentration of each drug. Samples from syringes and IV bags were subjected to standard sterility testing by incubation for 5 days in an enriched culture media. No notable changes in pH or colour were observed, and no precipitation occurred in any of the solutions. All formulations maintained more than 90% of the initial concentration of each drug on day 7. No bacterial growth was observed in any of the samples tested. Mixtures of hydromorphone and ketamine were stable for up 7 days at 25°C, and the sterility of the preparations was maintained. Because stability alone does not guarantee efficacy, it is recommended that clinical studies be conducted to evaluate the pharmacokinetics and pharmacodynamics of these formulations.

The stability of clay using Portland cement and calsium carbide residue with California bearing ratio (cbr) value

NASA Astrophysics Data System (ADS)

Puji Hastuty, Ika; Roesyanto; Novia Sari, Intan; Simanjuntak, Oberlyn

2018-03-01

Clay is a type of soil which is often used for stabilization. This is caused by its properties which are very hard in dry conditions and plastic in the medium content of water. However, at a higher level of water, clay will be cohesive and very lenient causing a large volume change due to the influence of water and also causing the soil to expand and shrink for a short period of time. These are the reasons why stabilization is needed in order to increase bearing capacity value of the clay. Stabilization is one of the ways to the conditon of soil that has the poor index properties, for example by adding chemical material to the soil. One of the chemical materials than can be added to the soil is calsium carbide residue. The purpose of this research is to know the fixation of index properties as the effect of adding 2% PC and calsium carbide residue to the clay, and to know the bearing capacity value of CBR (California Bearing Ratio) as the effect of adding the stabilization agent and to know the optimum content of adding calsium carbide residue. The result of the research shows that the usage of 2% cement in the soil that has CBR value 5,76%, and adding 2% cement and 9% calsium carbide residue with a period of curing 14 days has the lagerst of CBR value that is 9,95%. The unsoaked CBR value shows the increase of CBR value upto the mixture content of calsium carbide residue 9% and, decreases at the mixture content of calsium carbide residue 10% and 11%.

Dielectric and physiochemical study of binary mixture of nitrobenzene with toluene

NASA Astrophysics Data System (ADS)

Mohod, Ajay G.; Deshmukh, S. D.; Pattebahadur, K. L.; Undre, P. B.; Patil, S. S.; Khirade, P. W.

2018-05-01

This paper presents the study of binary mixture of Nitrobenzene (NB) with Toluene (TOL) for eleven different concentrations at room temperature. The determined Dielectric Constant (ɛ0) Density (ρ) and Refractive index (nD) values of binary mixture are used to calculate the excess properties i.e. Excess Dielectric Constant (ɛ0E), Excess Molar Volume (VmE), Excess Refractive Index (nDE) and Excess Molar Refraction (RmE) of mixture over the entire composition range and fitted to the Redlich-Kister equation. The Kirkwood Correlation Factor (geff) and other parameters were used to discuss the information about the orientation of dipoles and the solute-solvent interaction of binary mixture at molecular level over the entire range of concentration.

[Effect of triester glycerol type of plasticizers on release of albumin from biodegradable polymer matrices].

PubMed

Kladnícková, I; Klein, T; Dittrich, M

2004-01-01

Bovine serum albumin was heterogeneously dispersed in the terpolymer of DL-lactic acid, glycolic acid, and mannitol. The terpolymeric carrier was plasticized by triacetin, tributyrin, or a mixture of triacetin with tricaprylin. Matrices were prepared by mixing a melt of the carrier with the plasticizer and albumin. Liberation was tested in 1/15 mol.l-1 phosphate buffer pH 7.4 and took place in two stages--the burst and the stage of the continual process. The burst represented 30% to 90% of liberated albumin. The second, continual stage began on day 4 of liberation and within ten days maximally 10% of the total amount of albumin was released. The course of liberation was most markedly influenced by the parameters of the oligoester carrier, its molecular weight, and the degree of branching. The total extent of albumin liberation was influenced partly by its irreversible adsorption on the carrier, partly by its polymerization. The extent of adsorption and polymerization of albumin was increased with the molecular weight of the carrier and decreased with the increasing degree of its branching. Albumin liberation was positively influenced by the presence of plasticizers in matrices, triacetin being demonstrated as the best one.

Volumetric Properties of the Mixture Pentafluoroethane C2HF5 + C2H4F2 1,1-Difluoroethane (LB1530, VMSD1541)

NASA Astrophysics Data System (ADS)

Cibulka, I.; Hnědkovský, L.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

This document is part of Subvolume A `Binary Liquid Systems of Nonelectrolytes' of Volume 23 `Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV `Physical Chemistry'. It corresponds to the data set LB1530 of the ELBT database.

A Note on Dalton's Law: Myths, Facts, and Implementation

ERIC Educational Resources Information Center

Missen, Ronald W.; Smith, William R.

2005-01-01

Dalton's law for gas mixtures provides one method for predicting the pressure-volume-temperature (PVT) behavior of a gas mixture from the PVT behavior of the individual pure gases that comprise it. An attempt is made to separate fact from myth, to enlarge on a treatment of possible cases for application, and to provide contemporary means on…

Human Factors Engineering Bibliographic Series. Volume 2: 1960-1964 Literature

DTIC Science & Technology

1966-10-01

flutter discrimination, melodic and temporal) binaural vs. monaural equipment and methods (e.g., anechoic chambers, audiometric devices, communication...brightness, duration, timbre, vocality) stimulus mixtures (e.g., harmonics, beats , combination tones, modulations) thresholds training, nonverbal--see Training...scales and aids) Beats --see Audition (stimulus mixtures) Bells--see Auditory (displays, nonverbal) Belts, Harnesses, and other Restraining Devices--see

Streamline Basal Application of Herbicide for Small-Stem Hardwood Control

Treesearch

James H. Miller

1990-01-01

Abstract. The effectiveness of low-volume b a s a lapplication of herbicide - "streamline" application - was evaluated on 25 hardwood species and loblolly pine. Test mixtures were step-wise rates of Garlon 4 mixed in diesel fuel with a penatrant added. Most comparisons tested 1O%, 20%, and 30% mixtures of Garlon 4, while tests with...

Dielectric and Excess Properties of Glycols with Formamide Binary Mixtures at Different Temperatures

NASA Astrophysics Data System (ADS)

Navarkhele, V. V.

2018-07-01

Dielectric constant measurements of glycol-formamide binary solutions with various concentrations have been carried out at different temperatures. The dielectric measurement has been achieved at 100 MHz frequency using a sensor which is based on frequency domain reflectomery technique. The excess dielectric constant, Kirkwood correlation factor and Bruggeman factor has also been reported for the binary mixtures. The results show that the dielectric constant of the mixtures increases with increase in the volume fraction of formamide and decreases with increase in temperature. The study also confirms the presence of intermolecular interaction, hydrogen bonding and orientation of the dipoles in the binary mixtures.

Additive mixture effects of estrogenic chemicals in human cell-based assays can be influenced by inclusion of chemicals with differing effect profiles.

PubMed

Evans, Richard Mark; Scholze, Martin; Kortenkamp, Andreas

2012-01-01

A growing body of experimental evidence indicates that the in vitro effects of mixtures of estrogenic chemicals can be well predicted from the estrogenicity of their components by the concentration addition (CA) concept. However, some studies have observed small deviations from CA. Factors affecting the presence or observation of deviations could include: the type of chemical tested; number of mixture components; mixture design; and assay choice. We designed mixture experiments that address these factors, using mixtures with high numbers of components, chemicals from diverse chemical groups, assays with different in vitro endpoints and different mixture designs and ratios. Firstly, the effects of mixtures composed of up to 17 estrogenic chemicals were examined using estrogenicity assays with reporter-gene (ERLUX) and cell proliferation (ESCREEN) endpoints. Two mixture designs were used: 1) a 'balanced' design with components present in proportion to a common effect concentration (e.g. an EC(10)) and 2) a 'non-balanced' design with components in proportion to potential human tissue concentrations. Secondly, the individual and simultaneous ability of 16 potential modulator chemicals (each with minimal estrogenicity) to influence the assay outcome produced by a reference mixture of estrogenic chemicals was examined. Test chemicals included plasticizers, phthalates, metals, PCBs, phytoestrogens, PAHs, heterocyclic amines, antioxidants, UV filters, musks, PBDEs and parabens. In all the scenarios tested, the CA concept provided a good prediction of mixture effects. Modulation studies revealed that chemicals possessing minimal estrogenicity themselves could reduce (negatively modulate) the effect of a mixture of estrogenic chemicals. Whether the type of modulation we observed occurs in practice most likely depends on the chemical concentrations involved, and better information is required on likely human tissue concentrations of estrogens and of potential modulators. Successful prediction of the effects of diverse chemical combinations might be more likely if chemical profiling included consideration of effect modulation.

Additive Mixture Effects of Estrogenic Chemicals in Human Cell-Based Assays Can Be Influenced by Inclusion of Chemicals with Differing Effect Profiles

PubMed Central

Evans, Richard Mark; Scholze, Martin; Kortenkamp, Andreas

2012-01-01

A growing body of experimental evidence indicates that the in vitro effects of mixtures of estrogenic chemicals can be well predicted from the estrogenicity of their components by the concentration addition (CA) concept. However, some studies have observed small deviations from CA. Factors affecting the presence or observation of deviations could include: the type of chemical tested; number of mixture components; mixture design; and assay choice. We designed mixture experiments that address these factors, using mixtures with high numbers of components, chemicals from diverse chemical groups, assays with different in vitro endpoints and different mixture designs and ratios. Firstly, the effects of mixtures composed of up to 17 estrogenic chemicals were examined using estrogenicity assays with reporter-gene (ERLUX) and cell proliferation (ESCREEN) endpoints. Two mixture designs were used: 1) a ‘balanced’ design with components present in proportion to a common effect concentration (e.g. an EC10) and 2) a ‘non-balanced’ design with components in proportion to potential human tissue concentrations. Secondly, the individual and simultaneous ability of 16 potential modulator chemicals (each with minimal estrogenicity) to influence the assay outcome produced by a reference mixture of estrogenic chemicals was examined. Test chemicals included plasticizers, phthalates, metals, PCBs, phytoestrogens, PAHs, heterocyclic amines, antioxidants, UV filters, musks, PBDEs and parabens. In all the scenarios tested, the CA concept provided a good prediction of mixture effects. Modulation studies revealed that chemicals possessing minimal estrogenicity themselves could reduce (negatively modulate) the effect of a mixture of estrogenic chemicals. Whether the type of modulation we observed occurs in practice most likely depends on the chemical concentrations involved, and better information is required on likely human tissue concentrations of estrogens and of potential modulators. Successful prediction of the effects of diverse chemical combinations might be more likely if chemical profiling included consideration of effect modulation. PMID:22912892

Measurement of breast volume is a useful supplement to select candidates for surgical breast reduction.

PubMed

Ikander, Peder; Drejøe, Jennifer Berg; Lumholt, Pavia; Sjøstrand, Helle; Matzen, Steen; Quirinia, Anne; Siersen, Hans Erik; Ringberg, Anita; Lambaa, Susanne; Hölmich, Lisbet Rosenkrantz

2014-01-01

The indication for breast reduction in a public welfare or an insurance paid setting depends on the severity of the subjective symptoms and the clinical evaluation. The purpose of this study was to evaluate the use of breast volume as an objective criterion to establish the indication for breast reduction surgery, thus establishing a standard decision basis that can be shared by surgeons and departments to secure patients fair and equal treatment opportunities. A total of 427 patients who were referred to three Danish public hospitals with breast hypertrophy in the period from January 2007 to March 2011 were included prospectively in the study. The patients' subjective complaints, height, weight and standard breast measurements were registered as well as the decision for or against surgery. Breast volume was measured using transparent plastic cups. Cut-off values for breast volume were calculated based on whether or not the patients were offered reduction surgery. Most patients (93%) with a breast volume below 800 cc were not offered surgery, while most with a volume exceeding 900 cc were offered surgery (94%). In the grey zone between 800 and 900 cc, the indication seemed to be less clear-cut, and additional parameters need to be included. Breast volume can be used as an objective criterion in addition to the presently used criteria. Breast volume can easily be measured and has become appreciated by plastic surgeons dealing with patients with breast hypertrophy as a tool which facilitates their decision-making and patients' acceptance of the decisions made. not relevant. not relevant.

NASA Tech Briefs, May 1993. Volume 17, No. 5

NASA Technical Reports Server (NTRS)

1993-01-01

Topics include: Advanced Composites and Plastics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences.

Mechanical properties of steel/kenaf (hybrid) fibers added into concrete mixtures

NASA Astrophysics Data System (ADS)

Baarimah, A. O.; Syed Mohsin, S. M.

2018-04-01

This paper investigates the potential advantages of adding hybrid steel-kenaf fibers to concrete mixtures. Compression and flexural test were conducted on six concrete mixtures at 28 days to investigate the mechanical properties of the concrete. The experimental work consists of six concrete mixtures, in which the first mixture was a control mixture without adding any fiber. The following five concrete mixtures contain a total of 1% of volume fraction for steel, kenaf and a mixture of steel-kenaf (hybrid) fibers. Three ratios were considered for hybrid fibers with the ratios of 0.25/0.75, 0.5/0.5 and 0.75/0.25 for steel and kenaf fibers, respectively. From the investigation, it was observed that fibers have minimal effect on compressive strength of the concrete. However, the findings suggest promising improvement on the flexural strength of the concrete added with hybrid fiber (up to 86%) as well as manages to change the mode of failure of the beam from brittle to a more ductile manner.

Computational upscaling of Drucker-Prager plasticity from micro-CT images of synthetic porous rock

NASA Astrophysics Data System (ADS)

Liu, Jie; Sarout, Joel; Zhang, Minchao; Dautriat, Jeremie; Veveakis, Emmanouil; Regenauer-Lieb, Klaus

2018-01-01

Quantifying rock physical properties is essential for the mining and petroleum industry. Microtomography provides a new way to quantify the relationship between the microstructure and the mechanical and transport properties of a rock. Studies reporting the use microtomographic images to derive permeability and elastic moduli of rocks are common; only rare studies were devoted to yield and failure parameters using this technique. In this study, we simulate the macroscale plastic properties of a synthetic sandstone sample made of calcite-cemented quartz grains using the microscale information obtained from microtomography. The computations rely on the concept of representative volume elements (RVEs). The mechanical RVE is determined using the upper and lower bounds of finite-element computations for elasticity. We present computational upscaling methods from microphysical processes to extract the plasticity parameters of the RVE and compare results to experimental data. The yield stress, cohesion and internal friction angle of the matrix (solid part) of the rock were obtained with reasonable accuracy. Computations of plasticity of a series of models of different volume-sizes showed almost overlapping stress-strain curves, suggesting that the mechanical RVE determined by elastic computations is also valid for plastic yielding. Furthermore, a series of models were created by self-similarly inflating/deflating the porous models, that is keeping a similar structure while achieving different porosity values. The analysis of these models showed that yield stress, cohesion and internal friction angle linearly decrease with increasing porosity in the porosity range between 8 and 28 per cent. The internal friction angle decreases the most significantly, while cohesion remains stable.

Intraoperative Comparison of Anatomical versus Round Implants in Breast Augmentation: A Randomized Controlled Trial.

PubMed

Hidalgo, David A; Weinstein, Andrew L

2017-03-01

The purpose of this randomized controlled trial was to determine whether anatomical implants are aesthetically superior to round implants in breast augmentation. Seventy-five patients undergoing primary breast augmentation had a round silicone implant of optimal volume, projection, and diameter placed in one breast and an anatomical silicone device of similar volume and optimal shape placed in the other. After intraoperative photographs were taken, the anatomical device was replaced by a round implant to complete the procedure. A survey designed to measure breast aesthetics was administered to 10 plastic surgeon and 10 lay reviewers for blind evaluation of the 75 cases. No observable difference in breast aesthetics between anatomical and round implants was reported by plastic surgeons in 43.6 percent or by lay individuals in 29.2 percent of cases. When a difference was perceived, neither plastic surgeons nor lay individuals preferred the anatomical side more often than the round side. Plastic surgeons judged the anatomical side superior in 51.1 percent of cases and the round side superior in 48.9 percent of cases (p = 0.496). Lay individuals judged the anatomical side superior in 46.7 percent of cases and the round side superior in 53.3 percent (p = 0.140). Plastic surgeons identified implant shape correctly in only 26.5 percent of cases. This study provides high-level evidence supporting no aesthetic superiority of anatomical over round implants. Given that anatomical implants have important and unique disadvantages, a lack of proven aesthetic superiority argues against their continued use in breast augmentation. Therapeutic, I.

Microstructure and mesh sensitivities of mesoscale surrogate driving force measures for transgranular fatigue cracks in polycrystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castelluccio, Gustavo M.; McDowell, David L.

The number of cycles required to form and grow microstructurally small fatigue cracks in metals exhibits substantial variability, particularly for low applied strain amplitudes. This variability is commonly attributed to the heterogeneity of cyclic plastic deformation within the microstructure, and presents a challenge to minimum life design of fatigue resistant components. Our paper analyzes sources of variability that contribute to the driving force of transgranular fatigue cracks within nucleant grains. We also employ crystal plasticity finite element simulations that explicitly render the polycrystalline microstructure and Fatigue Indicator Parameters (FIPs) averaged over different volume sizes and shapes relative to the anticipatedmore » fatigue damage process zone. Volume averaging is necessary to both achieve description of a finite fatigue damage process zone and to regularize mesh dependence in simulations. Furthermore, results from constant amplitude remote applied straining are characterized in terms of the extreme value distributions of volume averaged FIPs. Grain averaged FIP values effectively mitigate mesh sensitivity, but they smear out variability within grains. Furthermore, volume averaging over bands that encompass critical transgranular slip planes appear to present the most attractive approach to mitigate mesh sensitivity while preserving variability within grains.« less

Microstructure and mesh sensitivities of mesoscale surrogate driving force measures for transgranular fatigue cracks in polycrystals

DOE PAGES

Castelluccio, Gustavo M.; McDowell, David L.

2015-05-22

The number of cycles required to form and grow microstructurally small fatigue cracks in metals exhibits substantial variability, particularly for low applied strain amplitudes. This variability is commonly attributed to the heterogeneity of cyclic plastic deformation within the microstructure, and presents a challenge to minimum life design of fatigue resistant components. Our paper analyzes sources of variability that contribute to the driving force of transgranular fatigue cracks within nucleant grains. We also employ crystal plasticity finite element simulations that explicitly render the polycrystalline microstructure and Fatigue Indicator Parameters (FIPs) averaged over different volume sizes and shapes relative to the anticipatedmore » fatigue damage process zone. Volume averaging is necessary to both achieve description of a finite fatigue damage process zone and to regularize mesh dependence in simulations. Furthermore, results from constant amplitude remote applied straining are characterized in terms of the extreme value distributions of volume averaged FIPs. Grain averaged FIP values effectively mitigate mesh sensitivity, but they smear out variability within grains. Furthermore, volume averaging over bands that encompass critical transgranular slip planes appear to present the most attractive approach to mitigate mesh sensitivity while preserving variability within grains.« less

The influence of temperature on the formation of liquid fuel from Polypropylene plastic wastes

NASA Astrophysics Data System (ADS)

Martynis, M.; Mulyazmi; Praputri, E.; Witri, R.; Putri, N.

2018-03-01

The current trend of municipal waste management in urban areas is caused by rapid changes in social, economic, political and cultural life. As a non-biodegradable polymers that have become essential materials, plastic wastes have created a very serious environmental challenge because of the huge quantities and their disposal problems. Recycling of plastics is seen as one method for reducing environmental and resource depletion. The most attractive technique of plastics recycling is pyrolysis involving the degradation of the polymeric materials by heating in the absence of oxygen. This study investigated the characteristics of pyrolysis liquid fuel (PLF) produced from polypropylene plastic wastes with temperature variations. Pyrolisis was carried out on 200 grams of polypropylene waste plastics at the operating temperature of 200°C, 250°C, 300 °C and 350 °C for 45 minutes. The liquid products were found to have carbon chain length in the range of C8-C9, similar with gasoline. The maximum density, volume and calorific value of the oil obtained were 0.8 g/cm3, 61 ml and 1307 cal/gr, respectively.

Effects of plastic film residues on occurrence of phthalates and microbial activity in soils.

PubMed

Wang, Jun; Lv, Shenghong; Zhang, Manyun; Chen, Gangcai; Zhu, Tongbin; Zhang, Shen; Teng, Ying; Christie, Peter; Luo, Yongming

2016-05-01

Plastic film mulching has played an important role in Chinese agriculture, especially in vegetable production, but large amounts of film residues can accumulate in the soil. The present study investigated the effects of plastic film residues on the occurrence of soil PAEs and microbial activities using a batch pot experiment. PAE concentrations increased with increasing plastic film residues but the soil microbial carbon and nitrogen, enzyme activities and microbial diversity decreased significantly. At the end of the experiment the PAE concentrations were 0-2.02 mg kg(-1) in the different treatments. Soil microbial C and N, enzyme activities, AWCD value, and Shannon-Weaver and Simpson indices declined by about 28.9-76.2%, 14.9-59.0%, 4.9-22.7%, 23.0-42.0% and 1.8-18.7%, respectively. Soil microbial activity was positively correlated with soil PAE concentration, and soil PAE concentrations were impacted by plastic color and residue volume. Correlations among, and molecular mechanisms of, plastic film residues, PAE occurrence and microbial activity require further study. Copyright © 2016 Elsevier Ltd. All rights reserved.

Long-Term Plasticity of Neurotransmitter Release: Emerging Mechanisms and Contributions to Brain Function and Disease.

PubMed

Monday, Hannah R; Younts, Thomas J; Castillo, Pablo E

2018-04-25

Long-lasting changes of brain function in response to experience rely on diverse forms of activity-dependent synaptic plasticity. Chief among them are long-term potentiation and long-term depression of neurotransmitter release, which are widely expressed by excitatory and inhibitory synapses throughout the central nervous system and can dynamically regulate information flow in neural circuits. This review article explores recent advances in presynaptic long-term plasticity mechanisms and contributions to circuit function. Growing evidence indicates that presynaptic plasticity may involve structural changes, presynaptic protein synthesis, and transsynaptic signaling. Presynaptic long-term plasticity can alter the short-term dynamics of neurotransmitter release, thereby contributing to circuit computations such as novelty detection, modifications of the excitatory/inhibitory balance, and sensory adaptation. In addition, presynaptic long-term plasticity underlies forms of learning and its dysregulation participates in several neuropsychiatric conditions, including schizophrenia, autism, intellectual disabilities, neurodegenerative diseases, and drug abuse. Expected final online publication date for the Annual Review of Neuroscience Volume 41 is July 8, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The use of waste materials in asphalt concrete mixtures.

PubMed

Tuncan, Mustafa; Tuncan, Ahmet; Cetin, Altan

2003-04-01

The purpose of this study was to investigate (a) the effects of rubber and plastic concentrations and rubber particle sizes on properties of asphalt cement, (b) on properties of asphalt concrete specimens and (c) the effects of fly ash, marble powder, rubber powder and petroleum contaminated soil as filler materials instead of stone powder in the asphalt concrete specimens. One type of limestone aggregate and one penetration-graded asphalt cement (75-100) were used. Three concentrations of rubber and plastic (i.e. 5%, 10% and 20% of the total weight of asphalt cement), three rubber particle sizes (i.e. No. 4 [4.75mm] - 20 [0.85 mm], No. 20 [0.85mm] - 200 [0.075mm] and No. 4 [4.75mm] - 200 [0.075mm]) and one plastic particle size (i.e. No. 4 [4.75mm] - 10 [2.00mm]) were also used. It was found that while the addition of plastic significantly increased the strength of specimens, the addition of rubber decreased it. No. 4 [4.75mm] - 200 [0.075mm] rubber particles showed the best results with respect to the indirect tensile test. The Marshall stability and indirect tensile strength properties of plastic modified specimens increased. Marble powder and fly ash could be used as filler materials instead of stone powder in the asphalt concrete pavement specimens.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polymer waste comprising nylon 6 and a polyolefin or mixtures of polyolefins to sequentially recover monomers or other high value products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1994-01-01

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polymer waste comprising nylon 6 and a polyolefin or mixtures of polyolefins to sequentially recover monomers or other high value products

DOEpatents

Evans, R.J.; Chum, H.L.

1994-10-25

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.

Neural network hardware and software solutions for sorting of waste plastics for recycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanton, S.L.; Alam, M.K.; Hebner, G.A.

1992-12-31

While plastic recycling efforts have expanded during the past several years, the cost of recovering plastics is still a major impediment for recyclers. Several factors contribute to the prohibitive cost of recycled resins, including the present low marketability of products made with mixed recycled materials, and costs of collecting, sorting and reprocessing plastic materials. A method for automatic sorting of post-consumer plastics into pure polymer streams is needed to overcome the inaccuracies and low product throughput of the currently used method of hand sorting of waste plastics for recycling. The Society of Plastics has designated seven categories as recyclable: Polyethylenemore » terephthalate (PET); High Density Polyethylene (HDPE); Polyvinyl Chloride (PVC); Low Density Polyethylene (LDPE); Polypropylene (PP); Polystyrene (PS); and Other (mixtures, layered items, etc.). With these categories in mind, a system for sorting of waste plastics using near-infrared reflectance spectra and a backpropagation neural network classifier has been developed. A solution has been demonstrated in the laboratory using a high resolution, and relatively slow instrument. A faster instrument is being developed at this time. Neural network hardware options have been evaluated for use in a real-time industrial system. In the lab, a Fourier transform Near Infrared (FT-NIR) scanning spectrometer was used to gather reflectance data from various locations on samples of actual waste plastics. Neural networks were trained off-line with this data using the NeuralWorks Professional II Plus software package on a SparcStation 2. One of the successfully trained networks was used to compare the neural accelerator hardware options available. The results of running this ``worst case`` network on the neural network hardware will be presented. The AT&T ANNA chip and the Intel 80170NX chip development system were used to determine the ease of implementation and accuracies for this network.« less

Neural network hardware and software solutions for sorting of waste plastics for recycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanton, S.L.; Alam, M.K.; Hebner, G.A.

1992-01-01

While plastic recycling efforts have expanded during the past several years, the cost of recovering plastics is still a major impediment for recyclers. Several factors contribute to the prohibitive cost of recycled resins, including the present low marketability of products made with mixed recycled materials, and costs of collecting, sorting and reprocessing plastic materials. A method for automatic sorting of post-consumer plastics into pure polymer streams is needed to overcome the inaccuracies and low product throughput of the currently used method of hand sorting of waste plastics for recycling. The Society of Plastics has designated seven categories as recyclable: Polyethylenemore » terephthalate (PET); High Density Polyethylene (HDPE); Polyvinyl Chloride (PVC); Low Density Polyethylene (LDPE); Polypropylene (PP); Polystyrene (PS); and Other (mixtures, layered items, etc.). With these categories in mind, a system for sorting of waste plastics using near-infrared reflectance spectra and a backpropagation neural network classifier has been developed. A solution has been demonstrated in the laboratory using a high resolution, and relatively slow instrument. A faster instrument is being developed at this time. Neural network hardware options have been evaluated for use in a real-time industrial system. In the lab, a Fourier transform Near Infrared (FT-NIR) scanning spectrometer was used to gather reflectance data from various locations on samples of actual waste plastics. Neural networks were trained off-line with this data using the NeuralWorks Professional II Plus software package on a SparcStation 2. One of the successfully trained networks was used to compare the neural accelerator hardware options available. The results of running this worst case'' network on the neural network hardware will be presented. The AT T ANNA chip and the Intel 80170NX chip development system were used to determine the ease of implementation and accuracies for this network.« less

Biobased chemicals: the convergence of green chemistry with industrial biotechnology.

PubMed

Philp, Jim C; Ritchie, Rachael J; Allan, Jacqueline E M

2013-04-01

Policy issues around biobased chemicals are similar to those for biobased plastics. However, there are significant differences that arise from differences in production volumes and the more specific applications of most chemicals. The drivers for biobased chemicals production are similar to those for biobased plastics, particularly the environmental drivers. However, in Europe, biobased chemical production is further driven by the need to improve the competitiveness of the chemicals industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

Deep Phenotyping of Coarse Root Architecture in R. pseudoacacia Reveals That Tree Root System Plasticity Is Confined within Its Architectural Model

PubMed Central

Danjon, Frédéric; Khuder, Hayfa; Stokes, Alexia

2013-01-01

This study aims at assessing the influence of slope angle and multi-directional flexing and their interaction on the root architecture of Robinia pseudoacacia seedlings, with a particular focus on architectural model and trait plasticity. 36 trees were grown from seed in containers inclined at 0° (control) or 45° (slope) in a glasshouse. The shoots of half the plants were gently flexed for 5 minutes a day. After 6 months, root systems were excavated and digitized in 3D, and biomass measured. Over 100 root architectural traits were determined. Both slope and flexing increased significantly plant size. Non-flexed trees on 45° slopes developed shallow roots which were largely aligned perpendicular to the slope. Compared to the controls, flexed trees on 0° slopes possessed a shorter and thicker taproot held in place by regularly distributed long and thin lateral roots. Flexed trees on the 45° slope also developed a thick vertically aligned taproot, with more volume allocated to upslope surface lateral roots, due to the greater soil volume uphill. We show that there is an inherent root system architectural model, but that a certain number of traits are highly plastic. This plasticity will permit root architectural design to be modified depending on external mechanical signals perceived by young trees. PMID:24386227

Computational study of Drucker-Prager plasticity of rock using microtomography

NASA Astrophysics Data System (ADS)

Liu, J.; Sarout, J.; Zhang, M.; Dautriat, J.; Veveakis, M.; Regenauer-Lieb, K.

2016-12-01

Understanding the physics of rocks is essential for the industry of mining and petroleum. Microtomography provides a new way to quantify the relationship between the microstructure and their mechanical and transport properties. Transport and elastic properties have been studied widely while plastic properties are still poorly understood. In this study, we analyse a synthetic sandstone sample for its up-scaled plastic properties from the micro-scale. The computations are based on the representative volume element (RVE). The mechanical RVE was determined by the upper and lower bound finite element computations of elasticity. By comparing with experimental curves, the parameters of the matrix (solid part), which consists of calcite-cemented quartz grains, were investigated and quite accurate values obtained. Analyses deduced the bulk properties of yield stress, cohesion and the angle of friction of the rock with pores. Computations of a series of models of volume-sizes from 240-cube to 400-cube showed almost overlapped stress-strain curves, suggesting that the mechanical RVE determined by elastic computations is valid for plastic yielding. Furthermore, a series of derivative models were created which have similar structure but different porosity values. The analyses of these models showed that yield stress, cohesion and the angle of friction linearly decrease with the porosity increasing in the range of porosity from 8% to 28%. The angle of friction decreases the fastest and cohesion shows the most stable along with porosity.

Room temperature deformation mechanisms of alumina particles observed from in situ micro-compression and atomistic simulations.

DOE PAGES

Sarobol, Pylin; Chandross, Michael E.; Carroll, Jay D.; ...

2015-09-22

Aerosol deposition (AD) is a solid-state deposition technology that has been developed to fabricate ceramic coatings nominally at room temperature. Sub-micron ceramic particles accelerated by pressurized gas impact, deform, and consolidate on substrates under vacuum. Ceramic particle consolidation in AD coatings is highly dependent on particle deformation and bonding; these behaviors are not well understood. In this work, atomistic simulations and in situ micro-compressions in the scanning electron microscope, and the transmission electron microscope (TEM) were utilized to investigate fundamental mechanisms responsible for plastic deformation/fracture of particles under applied compression. Results showed that highly defective micron-sized alumina particles, initially containingmore » numerous dislocations or a grain boundary, exhibited no observable shape change before fracture/fragmentation. Simulations and experimental results indicated that particles containing a grain boundary only accommodate low strain energy per unit volume before crack nucleation and propagation. In contrast, nearly defect-free, sub-micron, single crystal alumina particles exhibited plastic deformation and fracture without fragmentation. Dislocation nucleation/motion, significant plastic deformation, and shape change were observed. Simulation and TEM in situ micro-compression results indicated that nearly defect-free particles accommodate high strain energy per unit volume associated with dislocation plasticity before fracture. As a result, the identified deformation mechanisms provide insight into feedstock design for AD.« less

TEM-nanoindentation studies of semiconducting structures.

PubMed

Le Bourhis, E; Patriarche, G

2007-01-01

This paper reviews the application of nanoindentation coupled with transmission electron microscopy (TEM) to investigations of the plastic behaviour of semiconducting structures and its implication for device design. Instrumented nanoindentation has been developed to extract the mechanical behaviour of small volumes scaled to those encountered in semiconductor heterostructures. We illustrate that TEM is a powerful complementary tool for the study of local plasticity induced by nanoindentation. TEM-nanoindentation allows for detailed understanding of the plastic deformation in semiconducting structures and opens practical routes for improvement of devices. Performances of heterostructures are deteriously affected by dislocations that relax the lattice mismatched layers. Different ways to obtain compliant substructures are being developed in order to concentrate the plastic relaxation underneath the heterostructure. Such approaches allow for mechanical design of micro- and opto-electronic devices to be considered throughout the fabrication process.

Microdamage healing in asphalt and asphalt concrete, Volume 4 : a viscoelastic continuum damage fatigue model of asphalt concrete with microdamage healing

DOT National Transportation Integrated Search

2001-06-01

A mechanistic approach to fatigue characterization of asphalt-aggregate mixtures is presented in this volume. This approach is founded on a uniaxial viscoelastic correspondence principle is applied in order to evaluate damage growth and healing in cy...

Multi-stage Continuous Culture Fermentation of Glucose-Xylose Mixtures to Fuel Ethanol using Genetically Engineered Saccharomyces cerevisiae 424A

EPA Science Inventory

Multi-stage continuous (chemostat) culture fermentation (MCCF) with variable fermentor volumes was carried out to study utilizing glucose and xylose for ethanol production by means of mixed sugar fermentation (MSF). Variable fermentor volumes were used to enable enhanced sugar u...

Gas Separation Using Organic-Vapor-Resistent Membranes In Conjunctin With Organic-Vapor-Selective Membranes

DOEpatents

Baker, Richard W.; Pinnau, Ingo; He, Zhenjie; Da Costa, Andre R.; Daniels, Ramin; Amo, Karl D.; Wijmans, Johannes G.

2003-06-03

A process for treating a gas mixture containing at least an organic compound gas or vapor and a second gas, such as natural gas, refinery off-gas or air. The process uses two sequential membrane separation steps, one using membrane selective for the organic compound over the second gas, the other selective for the second gas over the organic vapor. The second-gas-selective membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons. The membrane steps can be combined in either order.

Multi-scale Rule-of-Mixtures Model of Carbon Nanotube/Carbon Fiber/Epoxy Lamina

NASA Technical Reports Server (NTRS)

Frankland, Sarah-Jane V.; Roddick, Jaret C.; Gates, Thomas S.

2005-01-01

A unidirectional carbon fiber/epoxy lamina in which the carbon fibers are coated with single-walled carbon nanotubes is modeled with a multi-scale method, the atomistically informed rule-of-mixtures. This multi-scale model is designed to include the effect of the carbon nanotubes on the constitutive properties of the lamina. It included concepts from the molecular dynamics/equivalent continuum methods, micromechanics, and the strength of materials. Within the model both the nanotube volume fraction and nanotube distribution were varied. It was found that for a lamina with 60% carbon fiber volume fraction, the Young's modulus in the fiber direction varied with changes in the nanotube distribution, from 138.8 to 140 GPa with nanotube volume fractions ranging from 0.0001 to 0.0125. The presence of nanotube near the surface of the carbon fiber is therefore expected to have a small, but positive, effect on the constitutive properties of the lamina.